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Biomedical subjects

A van den Broek

Publications and source records attributed to A van den Broek.

5 recordsLinked to original sources

The EMBL nucleotide sequence database.

The EMBL Nucleotide Sequence Database (http://www.ebi.ac.uk/embl/) is maintained at the European Bioinformatics Institute (EBI) in an international collaboration with the DNA Data Bank of Japan (DDBJ) and GenBank at the NCBI (USA). Data is exchanged amongst the collaborating databases on a daily basis. The major contributors to the EMBL database are individual authors and genome project groups. Webin is the preferred web-based submission system for individual submitters, whilst automatic procedures allow incorporation of sequence data from large-scale genome sequencing centres and from the European Patent Office (EPO). Database releases are produced quarterly. Network services allow free access to the most up-to-date data collection via ftp, email and World Wide Web interfaces. EBI's Sequence Retrieval System (SRS), a network browser for databanks in molecular biology, integrates and links the main nucleotide and protein databases plus many specialized databases. For sequence similarity searching a variety of tools (e.g. Blitz, Fasta, BLAST) are available which allow external users to compare their own sequences against the latest data in the EMBL Nucleotide Sequence Database and SWISS-PROT.

Computational Biology↗

Approaches to vaccines for Psoroptes ovis (sheep scab).

A brief outline of the history of sheep scab in the UK is presented together with the current chemical methods used for its control and problems associated with these. Possible alternative approaches to control are discussed, as are selected aspects of the physiology of Psoroptes ovis and the pathogenesis of the scab lesion from the perspective of control through immunisation. Evidence is provided that immunity to the disease can indeed be acquired, both naturally after a previous infection and following inoculation of mite proteins in adjuvant. These results support the view that control by vaccination may be possible, although little is known to date about the antigens involved or the mechanism of protection.

Animal Feed↗

The EMBL nucleotide sequence database.

The European Molecular Biology Laboratory (EMBL) Nucleotide Sequence Database (http://www.ebi.ac. uk/embl/index.html ) is maintained at the European Bioinformatics Institute (EBI) in an international collaboration with the DNA Data Bank of Japan (DDBJ) and GenBank (USA). Data is exchanged amongst the collaborative databases on a daily basis. The major contributors to the EMBL database are individual authors and genome project groups. WEBIN is the preferred web-based submission system for individual submitters, whilst automatic procedures allow incorporation of sequence data from large-scale genome sequencing centres and from the European Patent Office (EPO). Database releases are produced quarterly. Network services allow free access to the most up-to-date data collection via Internet and WWW interfaces. EBI's Sequence Retrieval System (SRS) is a network browser for databanks in molecular biology, integrating and linking the main nucleotide and protein databases plus many specialised databases. For sequence similarity searching a variety of tools (e.g., BLITZ, FASTA, BLAST) are available which allow external users to compare their own sequences against the most currently available data in the EMBL Nucleotide Sequence Database and SWISS-PROT.

Classification↗

Regulation of expression of the Lactobacillus pentosus xylAB operon.

The xylose cluster of Lactobacillus pentosus consists of five genes, two of which, xylAB, form an operon and code for the enzymes involved in the catabolism of xylose, while a third encodes a regulatory protein, XylR. By introduction of a multicopy plasmid carrying the xyl operator and by disruption of the chromosomal xylR gene, it was shown that L. pentosus xylR encodes a repressor. Constitutive expression of xylAB in the xylR mutant is repressed by glucose, indicating that glucose repression does not require XylR. The xylR mutant displayed a prolonged lag phase compared to wild-type bacteria when bacteria were shifted from glucose to xylose medium. Differences in the growth rate in xylose medium at different stages of growth are not correlated with differences in levels of xylAB transcription in L. pentosus wild-type or xylR mutant bacteria but are positively correlated in Lactobacillus casei with a plasmid containing xylAB. Glucose repression was further investigated with a ccpA mutant. An 875-bp internal fragment of the ccpA gene of L. pentosus was isolated by PCR and used to construct a ccpA knockout mutant. Transcription analysis of L. pentosus xylA showed that CcpA is involved in glucose repression. CcpA was also shown to be involved in glucose repression of the alpha-amylase promoter of Lactobacillus amylovorus by demonstrating that glucose repression of the chloramphenicol acetyltransferase gene under control of the alpha-amylase promoter is strongly reduced in the L. pentosus ccpA mutant strain.

Bacterial Proteins↗