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Database on the structure of small ribosomal subunit RNA.

The database on small ribosomal subunit RNA structure contains (June 1994) 2824 nucleotide sequences. All these sequences are stored in the form of an alignment based on the adopted secondary structure model, which in turn is corroborated by the observation of compensating substitutions in the alignment. The complete database is made available to the scientific community through anonymous ftp on our server in Antwerp. A special effort was made to improve electronic retrieval and a program is supplied that allows to create different file formats. The database can also be obtained from the EMBL nucleotide sequence library.

Animals↗

Cloning and sequencing of a full-length sea bream (Sparus aurata) beta-actin cDNA.

A full-length cDNA clone encoding beta-actin (beta-actin) was isolated from a sea bream (Sparus aurata) liver cDNA library. Sequencing of this clone reveals an open reading frame encoding a 375 amino acid protein that shares a high degree of conservation to other known actins. The sea bream beta-actin sequence showed 98% identity to carp and human beta-actin and 95% and 94% identity to sea squirt and Dictyostelium cytoplasmic actins, respectively.

Actins↗

Pyrrolidone carboxyl peptidase from the hyperthermophilic Archaeon Pyrococcus furiosus: cloning and overexpression in Escherichia coli of the gene, and its application to protein sequence analysis.

A gene for a pyrrolidone carboxyl peptidase (Pcp: EC 3.4.19.3, pyroglutamyl peptidase), which removes amino-terminal pyroglutamyl residues from peptides and proteins, has been cloned from the hyperthermophilic Archaeon Pyrococcus furiosus using its cosmid protein library, sequenced, and expressed in Escherichia coli. The DNA sequence encodes a protein containing 208 amino acid residues with methionine at the N-terminus. Analysis of the recombinant protein expressed in E. coli, including amino acid sequence analysis from the N-terminus by automated Edman degradation and ionspray mass spectrometric analysis of the peptides generated by enzymatic digestions with lysylendopeptidase and Staphylococcus aureus V8 protease, showed its primary structure to be completely identical with that deduced from its cDNA sequence. Comparison of the amino acid sequence of P. furiosus Pcp (P.f.Pcp) with those of bacterial Pcps revealed that a high degree of sequence identity (more than 40%) and conservation of the amino acid residues comprising the catalytic triad, Cys142, His166, and Glu79. On the other hand, a unique short stretch sequence (positions around 175-185) that is absent in bacterial Pcps was found in P.f.Pcp. A similar stretch has also been reported recently in the amino acid sequence of Pcp from the hyperthermophilic Archaeon Thermococcus litoralis [Littlechild et al., in abstracts of the "International Congress on Exthermophiles '98" p. 58 (1998)]. To elucidate their contribution to the hyperthermostability of these enzymes, further structural studies are required.

Amino Acid Sequence↗

Alanyl aminopeptidase from human seminal plasma: purification, characterization, and immunohistochemical localization in the male genital tract.

Alanyl aminopeptidase (AAP) was purified to homogeneity from human seminal plasma. The calculated molecular weight of the purified enzyme was approximately 137,000+/-5,000 from light scattering, 140,000 (main) and 137,000 (minor) from non-denatured PAGE and 153,000 from SDS-PAGE in the absence or presence of 2-mercaptoethanol (2-ME). These findings suggest that the enzyme is monomeric in form in human seminal plasma. The enzyme hydrolyzed several amino acid 4-methyl-coumaryl-7-amide (MCA) substrates. The order of Kcat/Km values of AAP at optimal pH (pH 7.5) was Ala- > Lys-Ala- > or = Met- > Leu- > Phe- > Arg- > or = Arg-Arg- > Lys- > Gly-MCAs. AAP was potently inhibited by bestatin, leuhistin, actinonin, amastatin, and 1,10-phenanthroline. These findings suggest that AAP is an aminopeptidase. We determined that the amino acid sequence of the first 22 residues of the enzyme was Ser1-Thr-Thr-Pro-Ser5-Ala-Ser-Ala-Thr-Thr10-Asn-Pro-Al a-Ser-Ala15-Thr-Thr-Leu-Asp-Gln20-Ser-Lys-. This sequence was completely coincident with that downstream of the transmembrane site of human intestinal alanyl aminopeptidase N (CD13). We also isolated cDNA encoding AAP from human prostate cDNA library, sequenced its structure, and confirmed human seminal plasma AAP to be identical with alanyl aminopeptidase N. We postulated that native human seminal plasma alanyl aminopeptidase is released into the seminal plasma after the specific site is cleaved by elastase or an elastase-like enzyme. The enzyme level in human seminal plasma determined by single radial immunodiffusion was 5.2+/-3.2 mg/100 ml (mean+/-SD, n=20) in individuals 20-47 years of age. AAP was immunohistochemically stained in the luminal site-cell membrane of epithelial cells in the prostatic gland and ductuli efferentes of the testis.

Adult↗

5' flanking sequence of the human immediate early responsive gene ccn1 (cyr61) and mapping of polymorphic CA repeat sequence motifs in the human ccn1 (cyr61) locus.

AIMS: The human ccn1 (hccn; hcyr61) gene has been identified previously at the mRNA and protein level as a 1,25-dihydroxyvitamin D(3) and growth factor regulated gene in human osteoblasts. This study aimed to analyse genomic clones containing the human ccn1 (cyr61) gene and to provide the 5' flanking region. METHODS: Genomic clones were isolated by screening a lambda library and by array filter hybridisations of a genomic library. Sequencing was performed using the dye terminator method. Promoter activity was measured after transient transfection using a beta galactosidase assay. CA repeat motifs were studied by a combined PCR/fragment analysis protocol. RESULTS: The human 5' flanking region of 870 nucleotides contains several stretches with high homology to the mouse promoter as well as CA repeat motifs. This first report on the human 5' flanking sequence of the hccn1 (hcyr61) gene provides important insights into regulation pathways for the expression of this 1,25-dihydroxyvitamin D(3) and growth factor responsive early gene. A genomic clone containing the hccn1 (hcyr61) gene region also yielded a CA sequence located 3' of the ccn1 (cyr61) gene. This CA repeat and one of the CA repeat motifs in the promoter were studied in detail and found to be polymorphic. CONCLUSIONS: The 5' flanking sequence of the hccn1 (hcyr61) gene provides insights into the mechanisms of regulation of this immediate early gene product. The CA repeat polymorphisms within the gene region will be useful in the genetic study of disorders affecting bone metabolism.

Chromosome Mapping↗

Analysis of clones from a human cartilage cDNA library provides insight into chondrocyte gene expression and identifies novel candidate genes for the osteochondrodysplasias.

To begin to define the gene expression pattern in fetal cartilage and to identify uncharacterized candidate genes for the osteochondrodysplasias, we analyzed clones from a fetal cartilage cDNA library. Sequence analysis of 420 cDNA clones identified 210 clones derived from established genes but, for many of them, expression in cartilage had not been previously reported. Among the established genes were 14 genes known to produce skeletal abnormalities in either humans or mice when mutated. Thirty-two uncharacterized genes and their respective chromosomal positions were also identified. To further understand the expression profile of these genes in fetal cartilage, we constructed a cDNA microarray utilizing the clones. The microarray was used to determine which genes had higher expression in cartilage as compared with dedifferentiated, cultured chondrocytes. Many of the established genes, as well as five of the uncharacterized genes, had increased expression in cartilage, suggesting an important role for these genes in the differentiated state of chondrocytes. These data provide new candidate genes for the osteochondrodysplasias and demonstrate the usefulness of cartilage cDNA microarrays in expanding our understanding of the complexity of fetal cartilage gene expression.

Cartilage↗

Cloning and sequencing of a gene for Mucor rennin, an aspartate protease from Mucor pusillus.

The aspartate protease of Mucor pusillus (Mucor pusillus rennin; MPR) is a milk-clotting enzyme used in the cheese industry. The partial amino acid sequence of MPR was determined and oligonucleotide probes were synthesized for cloning of the MPR gene. A clone giving positive hybridization with the probes was selected from the cosmid library. Sequencing of the cloned DNA revealed an open reading frame of 1281 bp without introns which encodes 361 amino acids for the expected MPR with an NH2-terminal extension of 66 amino acids. MPR seems to be synthesized as a prepro enzyme.

Amino Acid Sequence↗

Homeobox containing genes in the nematode Caenorhabditis elegans.

We designed a unique 36-mer oligonucleotide probe, based on the most highly conserved amino acid sequences of Antennapedia-like homeodomains and the codon bias of Caenorhabditis elegans. This probe was then used to isolate four classes of genes from a C. elegans genomic library. Sequencing reveals that we have isolated three new homeobox genes, designated ceh-1, ceh-9 and ceh-10. The fourth homeobox gene, ceh-11, has recently been described by Schaller et al (Nucleic Acids Res. 18, 2033-2036). The amino acid sequence of ceh-1 is 87% similar to the honeybee H40 homeodomain, 85% similar to the Drosophila NK-1 homeodomain and 82% similar to the chicken CHox3 homeodomain. The sequence ceh-10 appears to be a member of the paired class of homeodomains. The other two sequences, ceh-9 and ceh-11, remain unclassified. Three of the four sequences have at least one intron within the homeobox region. Transcripts of ceh-10 and ceh-11 are present in embryonic RNA but are greatly diminished in later developmental stages. Three of the four new genes have been placed on the C. elegans genomic map.

Amino Acid Sequence↗

Protein sequence requirements for function of the human T-cell leukemia virus type 1 Rex nuclear export signal delineated by a novel in vivo randomization-selection assay.

The Rex protein of human T-cell leukemia virus type 1, like the functionally equivalent Rev protein of human immunodeficiency virus type 1, contains a leucine-rich activation domain that specifically interacts with the human nucleoporin-like Rab/hRIP cofactor. Here, this Rex sequence is shown to function also as a protein nuclear export signal (NES). Rex sequence libraries containing randomized forms of the activation domain/NES were screened for retention of the ability to bind Rab/hRIP by using the yeast two-hybrid assay. While the selected sequences differed widely in primary sequence, all were functional as Rex activation domains. In contrast, randomized sequences that failed to bind Rab/hRIP lacked Rex activity. The selected sequences included one with homology to the Rev activation domain/NES and a second that was similar to the NES found in the cellular protein kinase inhibitor alpha. A highly variant, yet fully active, activation domain sequence selected on the basis of Rab/hRIP binding retained full NES function even though this sequence preserved only a single leucine residue. In contrast, nonfunctional activation domain mutants that were unable to bind Rab/hRIP had also lost NES function. These data demonstrate that NES activity is a defining characteristic of the activation domains found in the Rev/Rex class of retroviral regulatory proteins and strongly support the hypothesis that the Rab/hRIP cofactor plays a critical role in mediating the biological activity of these NESs. In addition, these data suggest a consensus sequence for NESs of the Rev/Rex class.

Amino Acid Sequence↗

Organization of the rat UDP-glucuronosyltransferase, UDPGTr-2, gene and characterization of its promoter.

A lambda clone containing the entire gene and flanking sequences for a form of UDP-glucuronosyltransferase (UDPGTr-2) that glucuronidates testosterone and the foreign compounds, 4-hydroxybiphenyl and chloramphenicol, has been isolated from a rat liver genomic library. Sequence analysis of this clone revealed that the UDPGTr-2 gene is approximately 12 kilobase pairs in length and consists of six exons. All introns were found to interrupt protein coding regions of the gene. Four transcriptional start sites have been identified and are located 34, 35, 38, and 39 base pairs (bp) upstream of the translation initiation site. The 5'-flanking region of the gene contains a TATA-like sequence, CATAAA, 22 bp from the first transcription start site, potential AP-1 and v-MYB binding sites, and four sequence motifs that have been found in genes that are expressed predominantly in the liver. A 323-bp fragment encompassing these elements was fused upstream in both orientations to the coding sequence of placental alkaline phosphatase to assay promoter activity. Transient transfection of various cultured cell lines with the chimeric DNA demonstrated that this fragment, in the correct orientation, was able to function as an efficient promoter in the rat hepatoma cell lines Reuber H4-II-E and McA-RH7777. It was, however, inactive in hepatoma cell lines from two other species and in cell lines derived from other tissues. These results are consistent with the physiological expression of the rat UDPGTr-2 gene and suggest that the proximal 5'-flanking region of the gene may contain information which limits its expression to the liver.

Alkaline Phosphatase↗

Molecular responses of macrophages to porcine reproductive and respiratory syndrome virus infection.

The detailed mechanism(s) by which porcine reproductive and respiratory syndrome virus (PRRSV) impairs alveolar Mo homeostasis and function remains to be elucidated. We used differential display reverse-transcription PCR (DDRT-PCR) to identify molecular genetic changes within PRRSV-infected Mo over a 24 h post infection period. From over 4000 DDRT-PCR amplicons examined, 19 porcine-derived DDRT-PCR products induced by PRRSV were identified and cloned. Northern blot analysis confirmed that four gene transcripts were induced during PRRSV infection. PRRSV attachment and penetration alone did not induce these gene transcripts. DNA sequence revealed that one PRRSV-induced expressed sequence tag (EST) encoded porcine Mx1, while the remaining 3 clones represented novel ESTs. A full-length cDNA clone for EST G3V16 was obtained from a porcine blood cDNA library. Sequence data suggests that it encodes an ubiquitin-specific protease (UBP) that regulates protein trafficking and degradation. In pigs infected in vivo, upregulated transcript levels were observed for Mx1 and Ubp in lung and tonsils, and for Mx1 in tracheobronchial lymph node (TBLN). These tissues correspond to sites for PRRSV persistence, suggesting that the Mx1 and Ubp genes may play important roles in clinical disease during PRRSV infection.

Amino Acid Sequence↗

Sequence analysis of UTR and coding region of kappa-casein gene of Indian riverine buffalo (Bubalus bubalis).

In this study, complete nucleotide as well as derived amino acid sequence characterization of water buffalo (Bubalus bubalis) kappa-casein gene has been presented. Kappa-casein cDNA clones were identified and isolated from a buffalo lactating mammary gland cDNA library. Sequence analysis of kappa-casein cDNA revealed 850 nucleotides with an open reading frame (ORF) of 573 nucleotides, encoding mature peptide of 169 amino acids. The 5' untranslated region (UTR) comprised 71 nucleotides, while 3' UTR was of 206 nucleotides. A total of 11 nucleotide and seven amino acid changes were observed in, buffalo (Bubalus bubalis) as compared to cattle (Bos taurus), sheep (Ovis aries) and goat (Capra hircus). Among these nucleotide changes, eight were unique in buffalo as they were fully conserved in cattle, sheep and goat. Majority of the nucleotide changes and all the amino acid changes; 14 (Asp-Glu), 19(Asp/Ser-Asn), 96(Ala-Thr), 126(Ala-Val), 128(Ala/Gly-Val), 156(Ala/Pro-Val) and 168(Ala/Glu-Val) were limited to exon IV. Three glycosylation sites, Thr 131, Thr 133 and Thr 142 reported in cattle and goat kappa-casein gene were also conserved in buffalo, however, in sheep Thr 142 was replaced by Ala. Chymosin hydrolysis site, between amino acids Phe 105 and Met 106, important for rennet coagulation process, were found to be conserved across four bovid species. Buffalo kappa-casein with the presence of amino acids Thr 136 and Ala 148 seems to be an intermediate of "A" and "B" variants of cattle. Comparison with other livestock species revealed buffalo kappa-casein sharing maximum nucleotide (95.5%) and amino acid (92.6%) similarity with cattle, whereas with pig it showed least sequence similarity of 76.0% and 53.2%, respectively. Phylogenetic analysis based on both nucleotide and amino acid sequence indicated buffalo kappa-casein grouping with cattle, while sheep and goat forming a separate cluster close to them. The non-ruminant species viz. camel, horse and pig were distantly placed, in separate lineages.

Amino Acid Sequence↗

Characterization of a highly polymorphic region 5' to JH in the human immunoglobulin heavy chain.

A cloned DNA segment 1.25 kilobases (kb) upstream from the joining segments of the human heavy chain immunoglobulin gene revealed extensive polymorphic variation at this locus, and the polymorphic pattern was stably transmitted to the next generation. Genomic restriction analysis showed that the polymorphism was caused by insertions/deletions within an MspI/BamHI fragment. Sequencing of one allele, 848 base pairs (bp) long, revealed eleven 50-base-pair tandem repeats. A second allele, 648 bp long, was cloned from a human genomic cosmid library, sequenced, and found to contain four fewer repeats than the first allele. A survey of 186 chromosomes from unrelated individuals of primarily northern European descent revealed at least six alleles.

Alleles↗

Cloning and sequencing of a Xenopus homologue of the inducible orphan receptor NGFI-B.

A cDNA clone encoding the NGFI-B transcription factor, a growth factor inducible member of the steroid/thyroid receptor superfamily, has been isolated from a Xenopus neurula (stage 17 embryo) library. Sequencing of this clone reveals an open reading frame encoding a 577 amino acid protein. Comparisons with its counterparts in rat, mouse and human show that the Xenopus protein has a well conserved DNA binding domain whereas homology in the carboxy terminal region, which includes the putative ligand binding domain, is lower than that typically observed in members of the steroid/thyroid receptor superfamily. This relative lack of homology suggests that, in Xenopus, the as-yet uncharacterized ligand may have subtle distinctions from its mammalian counterparts.

Amino Acid Sequence↗

Regulation of Drosophila TRPL channels by immunophilin FKBP59.

Transient receptor potential and transient receptor potential-like (TRPL) are Ca(2+)-permeable cation channels found in Drosophila photoreceptor cells associated with large multimeric signaling complexes held together by the scaffolding protein, INAD. To identify novel proteins involved in channel regulation, Drosophila INAD was used as bait in a yeast two-hybrid screen of a Drosophila head cDNA library. Sequence analysis of one identified clone showed it to be identical to the Drosophila homolog of human FK506-binding protein, FKBP52 (previously known as FKBP59). To determine the function of dFKBP59, TRPL channels and dFKBP59 were co-expressed in Sf9 cells. Expression of dFKBP59 produced an inhibition of Ca(2+) influx via TRPL in fura-2 assays. Likewise, purified recombinant dFKBP59 produced a graded inhibition of TRPL single channel activity in excised inside-out patches when added to the cytoplasmic membrane surface. Immunoprecipitations from Sf9 cell lysates using recombinant tagged dFKBP59 and TRPL showed that these proteins directly interact with each other and with INAD. Addition of FK506 prior to immunoprecipitation resulted in a temperature-dependent dissociation of dFKBP59 and TRPL. Immunoprecipitations from Drosophila S2 cells and from fly head lysates demonstrated that dFKBP59, but not dFKBP12, interacts with TRPL in vivo. Likewise, INAD immunoprecipitates with dFKBP59 from S2 cell and head lysates. Immunocytochemical evaluation of thin sections of fly heads revealed specific FKBP immunoreactivity associated with the eye. Site-directed mutagenesis showed that mutations of P702Q or P709Q in the highly conserved TRPL sequence (701)LPPPFNVLP(709) eliminated interaction of the TRPL with dFKBP59. These results provide strong support for the hypothesis that immunophilin dFKBP59 is part of the TRPL-INAD signaling complex and plays an important role in modulation of channel activity via interaction with conserved leucyl-prolyl dipeptides located near the cytoplasmic mouth of the channel.

Amino Acid Motifs↗

Biochemical identification of cutaneous leishmanias by analysis of kinetoplast DNA. II. Sequence homologies in Leishmania kDNA.

Kinetoplast DNA (kDNA) has been isolated from the human cutaneous Leishmania isolates, L. tropica major, L. aethiopica and an unknown Kenyan isolate, Leishmania SP48. DNA sequence relationships among these isolates have been studied by restriction enzyme digestion and two phase hybridisation to Southern blots of kDNA covalently coupled to diazobenzyloxymethyl (DBM) paper. The results of this analysis confirm that rapid kDNA sequence evolution is occurring in the Old World leishmanias although some sequence conservation in defined regions of the mini-circle sequence is present. These results emphasise the danger of constructing a rigid Leishmania classification on buoyant density data alone. The covalent binding of kDNA electrophoretic separations to DBM paper permits the construction of a DNA sequence "library' which can be used in the classification and diagnosis of unknown Leishmania isolates.

Base Sequence↗

Cloning and characterization of a cDNA specific for bovine retina.

A retina-specific cDNA clone (pCR18) was selected from a bovine retinal cDNA library and characterized. The clone pCR18 consisted of 905 base pairs and hybridized to the mRNA of about 12S from the bovine retina, but not that from the brain or liver. The nucleotide sequence revealed a long open reading frame which encodes a 147 amino acid polypeptide of about 15,700 Da. No significant sequence homology with the predicted protein was found in the protein sequence library of about 3500. Messenger RNA which hybridized to pCR18 translated a polypeptide of about 19,000 Da in a reticulocyte translation system. Southern blot analysis indicated that the bovine genome contains a single copy of this gene. Furthermore, RNA dot analysis showed that the poly(A)+ RNA from the human retinoblastoma cell lines (Y79 and WERI) hybridized to pCR18, whose intensity was comparable to that of the bovine retina. In situ hybridization revealed that pCR18 was expressed mostly in some ganglion cells of the rat retina. The results suggest that cDNA clone (pCR18) encodes a protein specific for the retina and mRNA for pCR18 is mostly localized in the retinal ganglion cells and also expressed in the human retinoblastoma cells, although its function remains to be elucidated.

Animals↗

Bioinformatic mapping of AlkB homology domains in viruses.

BACKGROUND: AlkB-like proteins are members of the 2-oxoglutarate- and Fe(II)-dependent oxygenase superfamily. In Escherichia coli the protein protects RNA and DNA against damage from methylating agents. 1-methyladenine and 3-methylcytosine are repaired by oxidative demethylation and direct reversal of the methylated base back to its unmethylated form. Genes for AlkB homologues are widespread in nature, and Eukaryotes often have several genes coding for AlkB-like proteins. Similar domains have also been observed in certain plant viruses. The function of the viral domain is unknown, but it has been suggested that it may be involved in protecting the virus against the post-transcriptional gene silencing (PTGS) system found in plants. We wanted to do a phylogenomic mapping of viral AlkB-like domains as a basis for analysing functional aspects of these domains, because this could have some relevance for understanding possible alternative roles of AlkB homologues e.g. in Eukaryotes. RESULTS: Profile-based searches of protein sequence libraries showed that AlkB-like domains are found in at least 22 different single-stranded RNA positive-strand plant viruses, but mainly in a subgroup of the Flexiviridae family. Sequence analysis indicated that the AlkB domains probably are functionally conserved, and that they most likely have been integrated relatively recently into several viral genomes at geographically distinct locations. This pattern seems to be more consistent with increased environmental pressure, e.g. from methylating pesticides, than with interaction with the PTGS system. CONCLUSIONS: The AlkB domain found in viral genomes is most likely a conventional DNA/RNA repair domain that protects the viral RNA genome against methylating compounds from the environment.

Adenine↗