Differential regulation of L1 and L2 beta-lactamase expression in Stenotrophomonas maltophilia.
It has been reported that Stenotrophomonas maltophilia L1 and L2 beta-lactamase expression is coordinated. We have isolated S. maltophilia mutants where (i) L1 is constitutively hyper-expressed and L2 is inducible; (ii) L2 is hyper-expressed and L1 is inducible; and (iii) L1 and L2 are constitutively hyper-expressed. The frequency of isolating type 1 and 2 mutants is c. 10(-7), indicating that promoter mutations are probably not involved and providing strong evidence that L1 and L2 expression is not, after all, coordinated. The frequency of isolating type 3 mutants is c. 10(-9), however, implying that there is a significant overlap between the regulatory mechanisms.
Avison
Matthew B
MB
Bristol Centre for Antimicrobial Research and Evaluation, Department of Pathology and Microbiology, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, UK. matthewb.avison@bris.ac.uk
Higgins
Catherine S
CS
Ford
Peter J
PJ
von Heldreich
Charlotte J
CJ
Walsh
Timothy R
TR
Bennett
Peter M
PM
D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D006801:Humans; D009154:Mutation; D020615:Stenotrophomonas maltophilia / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
C088032:beta-lactamase L1; C425104:beta-lactamase L2; D001618:beta-Lactamases