Mutational analysis of the Streptococcus pneumoniae bimodular class A penicillin-binding proteins.
One group of penicillin target enzymes, the class A high-molecular-weight penicillin-binding proteins (PBPs), are bimodular enzymes. In addition to a central penicillin-binding-transpeptidase domain, they contain an N-terminal putative glycosyltransferase domain. Mutations in the genes for each of the three Streptococcus pneumoniae class A PBPs, PBP1a, PBP1b, and PBP2a, were isolated by insertion duplication mutagenesis within the glycosyltransferase domain, documenting that their function is not essential for cellular growth in the laboratory. PBP1b PBP2a and PBP1a PBP1b double mutants could also be isolated, and both showed defects in positioning of the septum. Attempts to obtain a PBP2a PBP1a double mutant failed. All mutants with a disrupted pbp2a gene showed higher sensitivity to moenomycin, an antibiotic known to inhibit PBP-associated glycosyltransferase activity, indicating that PBP2a is the primary target for glycosyltransferase inhibitors in S. pneumoniae.
Paik
J
J
Max-Planck Institut für Molekulare Genetik, D-14185 Berlin, Germany.
Kern
I
I
Lurz
R
R
Hakenbeck
R
R
D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects; D029968:Escherichia coli Proteins; D006602:Hexosyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D009097:Multienzyme Complexes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002267:Muramoylpentapeptide Carboxypeptidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000494:pharmacology; D010453:Peptide Synthases; D046928:Peptidoglycan Glycosyltransferase; D010458:Peptidyl Transferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D011994:Recombinant Proteins; C478699:penicillin-binding protein 2a, Streptococcus; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D046928:Peptidoglycan Glycosyltransferase; C478681:penicillin-binding protein 1B, E coli; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase; D002267:Muramoylpentapeptide Carboxypeptidase; D010453:Peptide Synthases