Author:
Hussain M,Carlino A,Madonna M J,Lampen J O
Abstract
The structural gene for beta-lactamase II (EC 3.5.2.6), a metallothioenzyme, from Bacillus cereus 569/H (constitutive for high production of the enzyme) was cloned in Escherichia coli, and the nucleotide sequence was determined. This is the first class B beta-lactamase whose primary structure has been reported. The amino acid sequence of the exoenzyme form, deduced from the DNA, indicates that beta-lactamase II, like other secreted proteins, is synthesized as a precursor with a 30-amino acid N-terminal signal peptide. The pre-beta-lactamase II (Mr, 28,060) is processed in E. coli and in B. cereus to a single mature protein (Mr, 24,932) which is totally secreted by B. cereus but in E. coli remains intracellular, probably in the periplasm. The expression of the gene in E. coli RR1 on the multicopy plasmid pRWHO12 was comparable to that in B. cereus, where it is presumably present as a single copy. The three histidine residues that are involved (along with the sole cysteine of the mature protein) in Zn(II) binding and hence in enzymatic activity against beta-lactams were identified. These findings will help to define the secondary structure, mechanism of action, and evolutionary lineage of B. cereus beta-lactamase II and other class B beta-lactamases.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference47 articles.
1. Abraham E. P. and S. G. Waley. 1979. -Lactamases from Bacillus cereus p. 311-338. In J. M. T. Hamilton-Miller and J. T. Smith (ed.) Beta-lactamases. Academic Press Inc. (London) Ltd. London.
2. Ambler R. P. 1979. Amino acid sequences of P-lactamases p. 99-125. In J. M. T. Hamilton-Miller and J. T. Smith (ed.) Beta-lactamases. Academic Press Inc. (London) Ltd. London.
3. The structure of P-lactamases;Ambler R. P.;Philos. Trans. R. Soc. London Ser. B,1980
4. Production of a variant of P-lactamase II with selectively decreased cephalosporinase activity by a mutant of Bacillus cereus 569/H/9;Baldwin G. S.;Biochem. J.,1980
5. Histidine residues as zinc ligands in P-lactamases II;Baldwin G. S.;Biochem. J.,1978
Cited by
103 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献