Penicillin-binding protein 2 is essential for expression of high-level vancomycin resistance and cell wall synthesis in vancomycin-resistant Staphylococcus aureus carrying the enterococcal vanA gene complex.
A combination of biochemical and genetic experiments were performed in order to better understand the mechanism of expression of high-level vancomycin resistance in Staphylococcus aureus. The transcription of pbp2 of the highly vancomycin- and oxacillin-resistant strain COLVA200 and its mutant derivative with inactivated mecA were put under the control of an inducible promoter, and the dependence of oxacillin and vancomycin resistance and cell wall composition on the concentration of the isopropyl-beta-D-thiogalactopyranoside inducer was determined. The results indicate that mecA--the genetic determinant of oxacillin resistance--while essential for oxacillin resistance, is not involved with the expression of vancomycin resistance. Penicillin binding protein 2A, the protein product of mecA, appears to be unable to utilize the depsipeptide cell wall precursor produced in the vancomycin-resistant cells for transpeptidation. The key penicillin binding protein essential for vancomycin resistance and for the synthesis of the abnormally structured cell walls characteristic of vancomycin-resistant S. aureus (A. Severin, K. Tabei, F. Tenover, M. Chung, N. Clarke, and A. Tomasz, J. Biol. Chem. 279:3398-3407, 2004) is penicillin binding protein 2.
Severin
Anatoly
A
The Rockefeller University, New York, New York 10021, USA.
Wu
Shang Wei
SW
Tabei
Keiko
K
Tomasz
Alexander
A
D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics*; D019729:Carbon-Oxygen Ligases / Q000096:biosynthesis* / Q000235:genetics*; D002473:Cell Wall / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003593:Cytoplasm / Q000378:metabolism; D016983:Enterococcus / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D010068:Oxacillin / Q000494:pharmacology; D010403:Penicillin Resistance / Q000235:genetics; D046915:Penicillin-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D010406:Penicillins / Q000494:pharmacology; D010457:Peptidoglycan / Q000302:isolation & purification / Q000378:metabolism; D013211:Staphylococcus aureus / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D014530:Uridine Diphosphate / Q000378:metabolism; D020713:Vancomycin Resistance / Q000235:genetics*
D001426:Bacterial Proteins; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D010457:Peptidoglycan; C071437:VanA ligase, Bacteria; D014530:Uridine Diphosphate; D019729:Carbon-Oxygen Ligases; D010068:Oxacillin