A second regulatory gene, blaR1, encoding a potential penicillin-binding protein required for induction of beta-lactamase in Bacillus licheniformis.
AUTOR(ES)
Kobayashi, T
RESUMO
A second regulatory locus (blaR1) required for the induction of beta-lactamase synthesis in Bacillus licheniformis 749 was cloned and sequenced. The gene was located on a 5.2-kilobase-pair SphI DNA fragment which also contained the beta-lactamase (blaP) and repressor (blaI) genes. Bacillus subtilis BD224 carrying these three genes synthesized beta-lactamase on exposure to cephalosporin C, whereas Escherichia coli HB101 carrying the genes did not show any detectable induction of the enzyme. An open reading frame of 1,803 bases was identified as the blaR1 gene by subcloning and DNA sequencing. The gene started 2 bases downstream of the termination codon of bla1 and was preceded by a putative Shine-Dalgarno sequence (AAGGA) with a spacing of 5 bases. The deduced blaR1 product (601 amino acids) had a molecular weight of 68,425. Five transmembrane regions were predicted from the hydrophobicity profile. The region around Phe-Ala-Pro-Ala-Ser-Thr-Tyr-Lys (amino acids 398 to 405), which appeared to be located outside the membrane, was homologous to the binding regions of penicillin-binding proteins, including the beta-lactamases. The segment of 22 amino acids from 400 to 421 showed more than 70% homology to the penicillin-binding region of PBP 2 of E. coli. The blaR1 gene encodes a potential penicillin receptor which is required for the induction of beta-lactamase in B. licheniformis 749.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=213680Documentos Relacionados
- Structure, function, and fate of the BlaR signal transducer involved in induction of beta-lactamase in Bacillus licheniformis.
- Identification of BlaR, the signal transducer for beta-lactamase production in Bacillus licheniformis, as a penicillin-binding protein with strong homology to the OXA-2 beta-lactamase (class D) of Salmonella typhimurium.
- Purification and DNA binding properties of the blaI gene product, repressor for the beta-lactamase gene, blaP, of Bacillus licheniformis.
- Penicillin-binding protein 2 is required for induction of the Citrobacter freundii class I chromosomal beta-lactamase in Escherichia coli.
- Transcriptional analysis of beta-lactamase regulation in Bacillus licheniformis.