Identification and characterization of the penicillin-binding protein 2a of Streptococcus pneumoniae and its possible role in resistance to beta-lactam antibiotics.
To further understand the role of penicillin-binding protein 2a (PBP 2a) of Streptococcus pneumoniae in penicillin resistance, we confirmed the identity of the protein as PBP 2a. The PBP 2a protein migrated electrophoretically to a position corresponding to that of PBP 2x, PBP 2a, and PBP 2b of S. pneumoniae and was absent in a pbp2a insertional mutant of S. pneumoniae. We found that the affinities of PBP 2a for penicillins were lower than for cephalosporins and a carbapenem. When compared with other S. pneumoniae PBPs, PBP 2a exhibited lower affinities for beta-lactam antibiotics, especially penicillins. Therefore, PBP 2a is a low-affinity PBP for beta-lactam antibiotics in S. pneumoniae.
Zhao
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Infectious Diseases Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285, USA. Zhao_Genshi@Lilly.Com
Meier
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Hoskins
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McAllister
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D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000378:metabolism*; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase / Q000378:metabolism*; D046915:Penicillin-Binding Proteins; D010453:Peptide Synthases; D010458:Peptidyl Transferases; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000378:metabolism*; D018440:beta-Lactam Resistance
D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; C478699:penicillin-binding protein 2a, Streptococcus; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D010453:Peptide Synthases