amino acid sequence; bacillus/*chemistry/enzymology; base sequence; cloning, molecular; dna mutational analysis; enzyme induction; molecular sequence data; protein conformation; signal transduction; beta-Lactamases/*metabolism
Abstract :
[en] The membrane-spanning protein BlaR is essential for the induction of beta-lactamase in Bacillus licheniformis. Its nature and location were confirmed by the use of an antiserum specific for its carboxy-terminal penicillin sensor, its function was studied by genetic dissection, and the structure of the penicillin sensor was derived from hydrophobic cluster analysis of the amino acid sequence by using, as a reference, the class A beta-lactamases with known three-dimensional structures. During the first 2 h after the addition of the beta-lactam inducer, full-size BlaR, bound to the plasma membrane, is produced, and then beta-lactamase is produced. By 2 h after induction, BlaR is present in various (membrane-bound and cytosolic) forms, and there is a gradual decrease in beta-lactamase production. The penicillin sensors of BlaR and the class D beta-lactamases show strong similarities in primary structures. They appear to have the same basic spatial disposition of secondary structures as that of the class A beta-lactamases, except that they lack several alpha helices and, therefore, have a partially uncovered five-stranded beta sheet and a more readily accessible active site. Alterations of BlaR affecting conserved secondary structures of the penicillin sensor and specific sites of the transducer annihilate beta-lactamase inducibility.
Research center :
CIP - Centre d'Ingénierie des Protéines - ULiège
Disciplines :
Biochemistry, biophysics & molecular biology
Author, co-author :
Zhu, Yingfang; Rutgers University (New Jersey) - RU > Waksman Institute
Englebert, Serge; Université de Liège - ULiège > Centre d'Ingénierie des Protéines
Joris, Bernard ; Université de Liège - ULiège > Centre d'ingénierie des protéines
Ghuysen, Jean-Marie ; Université de Liège - ULiège > Centre d'Ingénierie des Protéines
Kobayashi, Tetsuo; Université de Liège - ULg/The Institute of Physical and Chemical Research (Japan) > Institut de Chimie > Centre d'Ingénierie des Protéines
Lampen, J-Olivier; Rutgers University (New Jersey) - RU > Waksman Institute
Language :
English
Title :
Structure, function, and fate of the BlaR signal transducer involved in induction of β-lactamase in Bacillus licheniformis
Publication date :
01 October 1992
Journal title :
Journal of Bacteriology
ISSN :
0021-9193
eISSN :
1098-5530
Publisher :
American Society for Microbiology (ASM), Washington, United States - District of Columbia