Molecular and biochemical characterization of the chromosome-encoded class A beta-lactamase BCL-1 from Bacillus clausii.
A chromosomal beta-lactamase gene from Bacillus clausii NR, which is used as a probiotic, was cloned and expressed in Escherichia coli. It encodes a clavulanic acid-susceptible Ambler class A beta-lactamase, BCL-1, with a pI of 5.5 and a molecular mass of ca. 32 kDa. It shares 91% and 62% amino acid identity with the chromosomally encoded PenP penicillinases from B. clausii KSM-K16 and Bacillus licheniformis, respectively. The hydrolytic profile of this beta-lactamase includes penicillins, narrow-spectrum cephalosporins, and cefpirome. This chromosome-encoded enzyme was inducible in B. clausii, and its gene is likely related to upstream-located regulatory genes that share significant identity with those reported to be upstream of the penicillinase gene of B. licheniformis. The bla(BCL-1) gene was located next to the known chromosomal aadD2 gene and the erm34 gene, which encode resistance to aminoglycosides and macrolides, respectively. Similar genes were found in a collection of B. clausii reference strains.
Girlich
Delphine
D
Service de Bactériologie-Virologie, Hôpital de Bicêtre, 78 rue du Général Leclerc, 94275 K. Bicêtre Cedex, France.
Leclercq
Roland
R
Naas
Thierry
T
Nordmann
Patrice
P
D000595:Amino Acid Sequence; D001407:Bacillus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D003001:Cloning, Molecular; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D001618:beta-Lactamases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D001618:beta-Lactamases