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PubMed2005

Molecular cloning, characterization and expression of a novel Asr gene from Ginkgo biloba.

A new abscisic acid, stress and ripening (Asr) gene was cloned from Ginkgo biloba by rapid amplification of cDNA ends (RACE) method. The full-length cDNA of G. biloba Asr (designated as GbAsr) was 952 bp long and it contained a 543 bp open reading frame encoding a protein of 181 amino acids. GbASR was found to be rich in His, Lys, Glu and Ala, and it had extensive homology with those of other plant Asr genes via multiple alignment analysis. Phylogenetic tree analysis indicated that the GbASR had a closer relationship with ASR from pine, another gymnosperm species, than with angiosperm ASRs. Southern blot analysis indicated that GbAsr belonged to a small multigene family. RT-PCR analyses revealed that GbAsr had a distinct up-regulated transcript pattern in root, stem and leaf under mannitol, NaCl and ABA treatments. The recombinant GbASR protein was successfully expressed in E. coli strain with pET-32a vector, and the result showed that the molecular weight of the recombinant protein was about 20 kDa, a size in agreement with that of the predicted by bioinformatic analysis. The expression of the GbAsr in E. coli will facilitate further research on this gene.

Amino Acid Sequence↗

PubMed2005

Munich information center for protein sequences plant genome resources: a framework for integrative and comparative analyses 1(W).

With several plant genomes sequenced, the power of comparative genome analysis can now be applied. However, genome-scale cross-species analyses are limited by the effort for data integration. To develop an integrated cross-species plant genome resource, we maintain comprehensive databases for model plant genomes, including Arabidopsis (Arabidopsis thaliana), maize (Zea mays), Medicago truncatula, and rice (Oryza sativa). Integration of data and resources is emphasized, both in house as well as with external partners and databases. Manual curation and state-of-the-art bioinformatic analysis are combined to achieve quality data. Easy access to the data is provided through Web interfaces and visualization tools, bulk downloads, and Web services for application-level access. This allows a consistent view of the model plant genomes for comparative and evolutionary studies, the transfer of knowledge between species, and the integration with functional genomics data.

Computational Biology↗

PubMed2006

Genetic segregation of airway disease traits despite redundancy of calcium-activated chloride channel family members.

Complex airway diseases such as asthma and chronic obstructive pulmonary disease exhibit stereotyped traits (especially airway hyperreactivity and mucous cell metaplasia) that are variably expressed in each patient. Here, we used a mouse model for virus-induced long-term expression of these traits to determine whether individual traits can be genetically segregated and thereby linked to separate determinants. We showed that an F2 intercross population derived from susceptible and nonsusceptible mouse strains can manifest individual phenotypic extremes that exhibit one or the other disease trait. Functional genomic analysis of these extremes further indicated that a member of the calcium-activated chloride channel (CLCA) gene family designated mClca3 was inducible with mucous cell metaplasia but not airway hyperreactivity. In confirmation of this finding, we found that mClca3 gene transfer to mouse airway epithelium was sufficient to induce mucous cell metaplasia but not airway hyperreactivity. However, newly developed mClca3(-/-) mice exhibited the same degree of mucous cell metaplasia and airway hyperreactivity as wild-type mice. Bioinformatic analysis of the Clca locus led to the identification of mClca5, and gene transfer indicated that mClca5 also selectively drives mucous cell metaplasia. Thus, in addition to the capacity of CLCA family members to exhibit diverse functional activities, there is also preserved function so that more than one family member mediates mucous cell metaplasia. Nonetheless, Clca expression appears to be a selective determinant of mucous cell metaplasia so that shared homologies between CLCA family members may still represent a useful target for focused therapeutic intervention in hypersecretory airway disease.

Animals↗

PubMed2006

Identification and analysis of novel genes expressed in the mouse embryonic facial primordia.

Craniofacial anomalies are a common feature of human congenital dysmorphology syndromes, suggesting that genes expressed in the developing face are likely to play a wider role in embryonic development. To facilitate the identification of genes involved in embryogenesis, we previously constructed an enriched cDNA library by subtracting adult mouse liver cDNA from that of embryonic day (E)10.5 mouse pharyngeal arch cDNA. From this library, 273 unique clones were sequenced and known proteins binned into functional categories in order to assess enrichment of the library (1). We have now selected 31 novel and poorly characterised genes from this library and present bioinformatic analysis to predict proteins encoded by these genes, and to detect evolutionary conservation. Of these genes 61% (19/31) showed restricted expression in the developing embryo, and a subset of these was chosen for further in silico characterisation as well as experimental determination of subcellular localisation based on transient transfection of predicted full-length coding sequences into mammalian cell lines. Where a human orthologue of these genes was detected, chromosomal localisation was determined relative to known loci for human congenital disease.

Animals↗

PubMed2004

Switching desaturase enzyme specificity by alternate subcellular targeting.

The functionality, substrate specificity, and regiospecificity of enzymes typically evolve by the accumulation of mutations in the catalytic portion of the enzyme until new properties arise. However, emerging evidence suggests enzyme functionality can also be influenced by metabolic context. When the plastidial Arabidopsis 16:0Delta7 desaturase FAD5 (ADS3) was retargeted to the cytoplasm, regiospecificity shifted 70-fold, Delta7 to Delta9. Conversely, retargeting of two related cytoplasmic 16:0Delta9 Arabidopsis desaturases (ADS1 and ADS2) to the plastid, shifted regiospecificity approximately 25-fold, Delta9 to Delta7. All three desaturases exhibited Delta9 regiospecificity when expressed in yeast, with desaturated products found predominantly on phosphatidylcholine. Coexpression of each enzyme with cucumber monogalactosyldiacylglycerol (MGDG) synthase in yeast conferred Delta7 desaturation, with 16:1Delta7 accumulating specifically on the plastidial lipid MGDG. Positional analysis is consistent with ADS desaturation of 16:0 on MGDG. The lipid headgroup acts as a molecular switch for desaturase regiospecificity. FAD5 Delta7 regiospecificity is thus attributable to plastidial retargeting of the enzyme by addition of a transit peptide to a cytoplasmic Delta9 desaturase rather than the numerous sequence differences within the catalytic portion of ADS enzymes. The MGDG-dependent desaturase activity enabled plants to synthesize 16:1Delta7 and its abundant metabolite, 16:3Delta(7,10,13). Bioinformatics analysis of the Arabidopsis genome identified 239 protein families that contain members predicted to reside in different subcellular compartments, suggesting alternative targeting is widespread. Alternative targeting of bifunctional or multifunctional enzymes can exploit eukaryotic subcellular organization to create metabolic diversity by permitting isozymes to interact with different substrates and thus create different products in alternate compartments.

Arabidopsis↗

PubMed2002

EST analysis of mRNAs expressed in neurula of Chinese amphioxus.

Amphioxus, a cephalochordate, is the closest living relative to the vertebrates. In order to investigate the molecular mechanisms of the early embryogenesis of amphioxus, we constructed a neurula embryo cDNA library of Chinese amphioxus (Branchiostoma belcheri tsingtauense) and generated 5235 expressed sequenced tags in the present study. The initial ESTs consisted of 638 clusters and 1855 singletons, which revealed approximately 2493 unique genes in the data set. Of these sequences, 35.52% ESTs matched to known genes, 12.76% matched to other ESTs, and 51.71% had no match to any known sequences in GenBank. Interestingly we found homologous genes related to neural development and human disease. Bioinformatic analysis showed the direct evidence that the gene homologue found only in vertebrates in previous studies also exists in the amphioxus genome. This study provides a preliminary view of the gene information involved in the development of neurula embryos of Chinese amphioxus and helps our understanding of vertebrate evolution at gene level.

Animals↗

PubMed2005

Evolutionary process of stress response systems controlled by abscisic acid in photosynthetic organisms.

There are many serious problems causing a food crisis such as desertification, population explosion, and environmental destruction, suggesting that a severe food crisis will become reality across the globe. Therefore, the transgenic plants, which have tolerance to environmental stresses, may take on greater and greater importance in attempts to increase food production. Aquatic photosynthetic organisms, such as prokaryotic cyanobacteria and eukaryotic green algae, are considered as an evolutionary origin of higher plants and their basic metabolisms including photosynthesis are similar to higher plants. Thereby, stress responsive genes or reactions from these organisms may be exceedingly advantageous sources for creation of stress-tolerant transgenic plants. In this study, the physiological roles and biosynthesis of abscisic acid (ABA), well known as a signal molecule in the adaptation to environmental stresses, in microalgae were investigated from the point of the view of its functional evolution in the response to environmental stresses. Chlamydomonas reinhardtii, a green alga, and Synechocystis sp. PCC 6803, a cyanobacterium, were employed in this study as model organisms. It is expected that this comparative analysis will provide basic information for the creation of stress-tolerant transgenic plants. ABA may act in C. reinhardtii as a signal molecule to induce antioxidant reactions for elimination of reactive oxygen species, but not to induce specific response reactions to mitigate water stresses. In Synechocystis, on the other hand, exogenously added ABA did not influence the growth and gene expression. Moreover, ABA did not relieve growth suppression caused by water and oxidative stresses. From the carotenoid composition and bioinformatic analysis, it can be suggested that the ABA biosynthetic pathway generally found in higher plants exists completely in C. reinhardtii, but incompletely in Synechocystis.

Abscisic Acid↗

PubMed2006

Cloning, characterization and expression analysis of two Tetraodon nigroviridis interleukin-16 isoform genes.

Interleukin-16 (IL-16) is an important pro-inflammatory cytokine that functions as a chemoattractant factor and is well characterized in human and other mammals, but is largely unknown in fish. In the present study, two isoforms of pro-IL-16 homologues were cloned and characterized from pufferfish Tetraodon nigroviridis. The full-length T. nigroviridis pro-IL-16 isoform 1 cDNA exhibits 2453 bp in size including 291 bp 5'UTR (untranslated region), 1704 bp ORF (open reading frame) and 458 bp 3'UTR, while pro-IL-16 isoform 2 cDNA exhibits a 3801 bp ORF and a 458 bp 3'UTR. Bioinformatics analysis demonstrated that the pro-IL-16 isoform 1 with a predicted mass of 60.6 kDa contained two PDZ (postsynaptic density/disc large/zona occludens-1) domains, whereas the 138.2 kDa pro-IL-16 isoform 2 had two additional PDZ domains in its N-terminal extension. RT-PCR results revealed that ,almost in all examined organs and tissues, the mRNA of both pro-IL-16 isoforms can be detected, except in intestine and gill, where the isoform 2 mRNA is absent. The two putative precursor proteins showed 30.0-33.0% identity to various mammalian and avian homologues. This is the first report of such genes in teleostean fish and we hope the molecular characterization of these two pro-IL-16 isoforms will provide insights into the study of both evolution of IL-16 precursor proteins and the immune system as a whole.

Amino Acid Sequence↗

PubMed2006

Prediction of renal allograft rejection by urinary protein analysis using ProteinChip Arrays (surface-enhanced laser desorption/ionization time-of-flight mass spectrometry).

OBJECTIVES: To develop a noninvasive method for the detection of renal transplant rejection using ProteinChip Arrays (surface-enhanced laser desorption/ionization time-of-flight mass spectrometry). METHODS: A total of 23 urine samples were collected from 13 patients showing biopsy-proven renal allograft rejection and from 10 patients without histologic signs of rejection. All 23 patients had clinical symptoms and signs of acute allograft rejection and underwent renal biopsy. Samples were centrifuged, and supernatants were directly spotted onto the ProteinChip arrays with different chromatographic surfaces. The obtained spectra in a range from 2 to 200 kDa were subjected to bioinformatic analysis using the method of Fuzzy c-means, followed by the establishment of rule bases and evaluation using the relevance index according to Kiendl. RESULTS: Several protein peaks were identified allowing differentiation between rejection and no rejection. Using two different ProteinChip surfaces, we found two biomarkers at 25.71 kDa and 28.13 kDa that gave a diagnostic sensitivity of 90% and 93% and a specificity of 80% (SAX2) and 85% (CM10), respectively. CONCLUSIONS: Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry appears to be a promising new diagnostic tool for distinguishing renal transplant patients with no rejection from those with acute rejection.

Graft Rejection↗

PubMed2004

Molecular analysis of rugosity in a Vibrio cholerae O1 El Tor phase variant.

Reversible phase variation between the rugose and smooth colony variants is predicted to be important for the survival of Vibrio cholerae in natural aquatic habitats. Microarray expression profiling studies of the rugose and smooth variants of the same strain led to the identification of 124 differentially regulated genes. Further expression profiling experiments showed how these genes are regulated by the VpsR and HapR transcription factors, which, respectively, positively and negatively regulate production of VPS(El Tor), a rugose-associated extracellular polysaccharide. The study of mutants of rpoN and rpoS demonstrated the effects of these alternative sigma factors on phase variation-specific gene expression. Bioinformatics analysis of these expression data shows that 'rugosity' and 'smoothness' are determined by a complex hierarchy of positive and negative regulators, which also affect the biofilm, surface hydrophobicity and motility phenotypes of the organism.

Adaptation, Physiological↗

PubMed2003

Two families with familial amyotrophic lateral sclerosis are linked to a novel locus on chromosome 16q.

Amyotrophic lateral sclerosis (ALS) is a fatal adult-onset disease in which motor neurons in the brain and spinal cord degenerate by largely unknown mechanisms. ALS is familial (FALS) in 10% of cases, and the inheritance is usually dominant, with variable penetrance. Mutations in copper/zinc super oxide dismutase (SOD1) are found in 20% of familial and 3% of sporadic ALS cases. Five families with ALS and frontotemporal dementia (ALS-FTD) are linked to 9q21, whereas one family with pure ALS is linked to 18q21. We identified two large European families with ALS without SOD1 mutations or linkage to known FALS loci and conducted a genomewide linkage screen using 400 microsatellite markers. In both families, two-point LOD scores >1 and a haplotype segregating with disease were demonstrated only across regions of chromosome 16. Subsequent fine mapping in family 1 gave a maximum two-point LOD score of 3.62 at D16S3137 and a three-point LOD score of 3.85 for markers D16S415 and D16S3137. Haplotype analysis revealed no recombination > approximately 30 cM, (flanking markers at D16S3075 and D16S3112). The maximum two-point LOD score for family 2 was 1.84 at D16S415, and the three-point LOD score was 2.10 for markers D16S419 and D16S415. Definite recombination occurred in several individuals, which narrowed the shared haplotype in affected individuals to a 10.1-cM region (flanking markers: D16S3396 and D16S3112). The region shared by both families on chromosome 16q12 corresponds to approximately 4.5 Mb on the Marshfield map. Bioinformatic analysis of the region has identified 18 known genes and 70 predicted genes in this region, and sequencing of candidate genes has now begun.

Adult↗

PubMed2006

Structure-function analysis of Frizzleds.

Frizzleds, cell surface receptors that mediate the actions of Wnt ligands on early development, are heptahelical (based upon hydropathy analysis) and couple to heterotrimeric G proteins. The primary structure of all ten mammalian Frizzleds display many landmarks observed in virtually all G protein-coupled receptors, including an exofacial N-terminus that is N-glycosylated, the presence of seven hydrophobic transmembrane segments predicted to form alpha-helixes, and three intracellular loops as well as a cytoplasmic, C-terminal tail that harbor suspected sites for protein phosphorylation. Prediction of the G proteins to which Frizzleds mediate signaling based upon a bioinformatic analysis of the primary sequence of the intracellular domains are in good agreement with functional screens in Drosophila, zebrafish, and mouse models of development, e.g., predicting Frizzled-1 to interact with members of the Gi/Go protein family. Likewise various Wnt signaling pathways are sensitive to treatment with pertussis toxin and knock-down of specific G protein alpha-subunits. Homology among the sequences encoding the cytoplasmic domains of human Frizzleds is high and the various Frizzleds can be segregated into subsets predicted to share some common downstream signaling elements. Among different species, homologies can reveal conservation of signaling to cognate G protein partners. Additionally, cytoplasmic domains of the prototypic beta2-adrenergic receptor can be substituted with those from either Frizzled-1 or Frizzled-2 to create chimeric receptors that are activated by beta-adrenergic agonists, yet signal with high fidelity to the Wnt/beta-catenin and Wnt/Ca2+, cyclic GMP pathways, respectively, regulating key aspects of early development. The nature of Frizzled-based signaling complexes, their temporal assembly, and spatial distribution via scaffold protein remains to be elucidated, as does whether or not these Wnt receptors display agonist-induced desensitization, internalization, and re-cycling to the cell membrane.

Amino Acid Sequence↗

PubMed2003

Design of peptide mimetics of HIV-1 gp120 for prevention and therapy of HIV disease.

It has been reported that the C-terminus of the second conserved region (C2) of the envelope glycoprotein gp120, encompassing peptide RSANFTDNAKTIIVQLNESVEIN (NTM), is important for infectivity and neutralization of the human immunodeficiency virus type 1 (HIV-1). It was also demonstrated that human natural anti-vasoactive intestinal peptide (VIP) antibodies reactive with this gp120 region play an important role in control of HIV disease progression. The bioinformatic analysis based on the time-frequency signal processing revealed non-obvious similarities between NTM and VIP. When tested against a battery of sera from 46 AIDS patients, these peptides, in spite of a significant difference in their primary structures, showed a similar reactivity profiles (r = 0.83). Presented results point out that similarity in the periodical pattern of some physicochemical properties in primary structures of peptides plays a significant role in determination of their immunological crossreactivity. Based on these findings, we propose this bioinformatic criterion be used for design of VIP/NTM peptide mimetics for prevention and treatment of HIV disease.

Amino Acid Sequence↗

PubMed2006

The DtxR protein acting as dual transcriptional regulator directs a global regulatory network involved in iron metabolism of Corynebacterium glutamicum.

BACKGROUND: The knowledge about complete bacterial genome sequences opens the way to reconstruct the qualitative topology and global connectivity of transcriptional regulatory networks. Since iron is essential for a variety of cellular processes but also poses problems in biological systems due to its high toxicity, bacteria have evolved complex transcriptional regulatory networks to achieve an effective iron homeostasis. Here, we apply a combination of transcriptomics, bioinformatics, in vitro assays, and comparative genomics to decipher the regulatory network of the iron-dependent transcriptional regulator DtxR of Corynebacterium glutamicum. RESULTS: A deletion of the dtxR gene of C. glutamicum ATCC 13032 led to the mutant strain C. glutamicum IB2103 that was able to grow in minimal medium only under low-iron conditions. By performing genome-wide DNA microarray hybridizations, differentially expressed genes involved in iron metabolism of C. glutamicum were detected in the dtxR mutant. Bioinformatics analysis of the genome sequence identified a common 19-bp motif within the upstream region of 31 genes, whose differential expression in C. glutamicum IB2103 was verified by real-time reverse transcription PCR. Binding of a His-tagged DtxR protein to oligonucleotides containing the 19-bp motifs was demonstrated in vitro by DNA band shift assays. At least 64 genes encoding a variety of physiological functions in iron transport and utilization, in central carbohydrate metabolism and in transcriptional regulation are controlled directly by the DtxR protein. A comparison with the bioinformatically predicted networks of C. efficiens, C. diphtheriae and C. jeikeium identified evolutionary conserved elements of the DtxR network. CONCLUSION: This work adds considerably to our currrent understanding of the transcriptional regulatory network of C. glutamicum genes that are controlled by DtxR. The DtxR protein has a major role in controlling the expression of genes involved in iron metabolism and exerts a dual regulatory function as repressor of genes participating in iron uptake and utilization and as activator of genes responsible for iron storage and DNA protection. The data suggest that the DtxR protein acts as global regulator by controlling the expression of other regulatory proteins that might take care of an iron-dependent regulation of a broader transcriptional network of C. glutamicum genes.

Bacterial Proteins↗

PubMed2005

[Screening tumor antigens of ovarian carcinoma by Western blot, immunoprecipitation, and mass spectrometry].

BACKGROUND & OBJECTIVE: Screening tumor antigens plays a key role in early diagnosis of ovarian carcinoma. Several technologies, such as phage antibody library, ribosome display, and serological analysis of recombinant cDNA expression libraries (SEREX), have been applied widely. This study was to screen and identify tumor antigens of ovarian carcinoma by Western blot, immunoprecipitation, and mass spectrometry, and to establish a new methodological entity. METHODS: Western blot was used to find out the obviously different serum in ovarian carcinoma patients; SKOV3 cells lysate was added in the serum; immunoprecipitation was used to enrich antigens; then, the different protein band was gained when compared with normal serum immunoprecipitates, identified by mass spectrometry, and analyzed with bioinformatics. RESULTS: The serum of patient No. 7 was the obviously different one screened with Western blot. Immunoprecipitation and SDS-PAGE showed a different protein band in the serum appeared in the position of about 66.2 ku when compared with normal serum immunoprecipitates. Through mass spectrometry and bioinformatics analysis, heat shock protein 70 (HSP70) and cytokeratin 9 were identified in the different protein band. CONCLUSION: Western blot, immunoprecipitation, and mass spectrometry is an effectively methodological entity for screening and identifying tumor antigens.

Antigens, Neoplasm↗

PubMedDate not supplied

Prediction of enzyme family classes.

Classes of newly found enzyme sequences are usually determined either by biochemical analysis of eukaryotic and prokaryotic genomes or by microarray chips. These experimental methods are both time-consuming and costly. With the explosion of protein sequences entering into databanks, it is highly desirable to explore the feasibility of selectively classifying newly found enzyme sequences into their respective enzyme classes by means of an automated method. This is indeed important because knowing which family or subfamily an enzyme belongs to may help deduce its catalytic mechanism and specificity, giving clues to the relevant biological function. In this study, a bioinformatical analysis was conducted for 2640 oxidoreductases classified into 16 subclasses according to the different types of substrates they act on during the catalytic process. Although it is an extremely complicated problem and might involve the knowledge of 3-dimensional structure as well as many other physical chemistry factors, some quite promising results have been obtained indicating that the family or subfamily of an enzyme is predictable to a considerable degree by means of sequence-based approach alone if a good training dataset can be established.

Amino Acid Sequence↗

PubMed2026

Human periodontal ligament stem cells promote oral ulcer healing in rats through modulation of TGF-β1/smad signaling.

BACKGROUND: Oral ulcers (OU) often present with prolonged healing, recurrent episodes, and scar formation, posing challenges for clinical management. Human periodontal ligament stem cells (hPDLSCs) have shown potential in oral tissue repair, but further research is needed to clarify their mechanism of action in OU healing. This study aims to elucidate the molecular mechanisms by which hPDLSCs promote oral ulcer healing. METHOD: To identify key regulatory genes, the OU-associated microarray dataset GSE37265 was integrated with hPDLSC genomic data for differential expression analysis. Subsequently, Weighted Gene Co-expression Network Analysis (WGCNA) was used to identify functional modules associated with OU healing. In vivo, hPDLSCs were locally administered into a rat ulcer model, and therapeutic efficacy was assessed by ulcer closure rates and histological evaluation (HE and Masson's trichrome staining). Furthermore, RNA-sequencing (RNA-seq) was performed on oral mucosal tissues to delineate the underlying molecular landscape and critical signaling pathways. The involvement of the TGF-β signaling pathway was confirmed by real-time quantitative PCR (RT-qPCR) and Western blotting (WB) analyses. RESULTS: Bioinformatics analysis identified 92 key genes in hPDLSCs-mediated treatment of OU, highlighting the central role of the TGF-β1/Smad pathway. As shown by the animal studies, hPDLSCs therapy increased the healing rate to 97% by day 8 (vs. 70% in the model). Furthermore, the therapy significantly reduced inflammatory cell infiltration and abnormal collagen deposition while promoting regular collagen arrangement. Transcriptomic and molecular experiments further showed that hPDLSCs simultaneously inhibit TGF-β1/Smad and extracellular signal-regulated kinase (ERK) signaling pathways, thereby alleviating inflammatory responses and suppressing mucosal fibrosis. CONCLUSION: In this study, we reveal a novel role for hPDLSCs in promoting oral ulcer healing. The findings indicate that hPDLSCs suppress inflammation and fibrosis via the TGF-β1/Smad pathway, offering a promising therapeutic strategy for OU and other fibrotic conditions.

TGF-β1↗

PubMed2002

Virulence gene identification by differential fluorescence induction analysis of Staphylococcus aureus gene expression during infection-simulating culture.

We have employed a strategy utilizing differential fluorescence induction (DFI) in an effort to identify Staphylococcus aureus genes whose products can be targeted for antimicrobial drug development. DFI allows identification of promoters preferentially active under given growth conditions on the basis of their ability to drive expression of a promoterless green fluorescent protein gene (gfp). A plasmid-based promoter trap library was constructed of 200- to 1,000-bp fragments of S. aureus genomic DNA fused to gfp, and clones with active promoters were isolated under seven different in vitro growth conditions simulating infection. Six thousand two hundred sixty-seven clones with active promoters were screened to identify those that exhibited differential promoter activity. Bioinformatic analysis allowed the identification of 42 unique operons, containing a total of 61 genes, immediately downstream of the differentially active putative promoters. Replacement mutations were generated for most of these operons, and the abilities of the resulting mutants to cause infection were assessed in two different murine infection models. Approximately 40% of the mutants were attenuated in at least one infection model.

Abscess↗