Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The gene, prs, encoding phosphoribosylpyrophosphate (PRPP) synthetase of Escherichia coli was isolated from a library of E. coli genes cloned in the bacteriophage lambda D69 vector. A strain with a temperature-lethal defect in PRPP synthetase, (prs-2), was used as the host and cloning was performed by lysogenic complementation. The prs gene resided on a 5.6 kilobase-pair (kbp) DNA fragment generated by hydrolysis with restriction endonuclease BamHI. The nearby gene pth, encoding peptidyl-tRNA hydrolase, was also on this fragment. Subcloning of the fragment in the multi-copy plasmid pBR322 and subsequent deletion of parts of the insert resulted in a 1.7 kbp DNA fragment containing the entire prs gene. Bacterial strains harbouring prs-bearing plasmids showed up to 50-fold increased PRPP synthetase activity. The PRPP synthetase subunit was identified by analysis of plasmid-harbouring minicells and the subunit molecular mass established as 33,000 daltons. Analysis, by the minicell procedure, of plasmids with deletions extending into the prs gene established the direction of transcription as counterclockwise. A putative leader sequence of approximately 400 bp preceded the coding sequence. By deletion analysis and by cloning fragments of this leader sequence in a galK expression vector it was found to contain the prs promoter as well as a potential transcription termination site.
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PMID:Cloning and characterization of the prs gene encoding phosphoribosylpyrophosphate synthetase of Escherichia coli. 300 29

The gene (prs) encoding phosphoribosylpyrophosphate (PRPP) synthetase has been cloned from a library of Bacillus subtilis DNA by complementation of an Escherichia coli prs mutation. Flanking DNA sequences were pruned away by restriction endonuclease and exonuclease BAL 31 digestions, resulting in a DNA fragment of approx. 1.8 kb complementing the E. coli prs mutation. Minicell experiments revealed that this DNA fragment coded for a polypeptide, shown to be the PRPP synthetase subunit, with an Mr of approx. 40,000. B. subtilis strains harbouring the prs gene in a multicopy plasmid contained up to nine-fold increased PRPP synthetase activity. The prs gene was cloned in an integration vector and the resulting hybrid plasmid inserted into the B. subtilis chromosome by homologous recombination. The integration site was mapped by transduction and the gene order established as purA-guaA-prs-cysA.
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PMID:Phosphoribosylpyrophosphate synthetase of Bacillus subtilis. Cloning, characterization and chromosomal mapping of the prs gene. 303 93