<prompt> All of the following statements about Penicillin Binding Proteins PBPs are true, EXCEPT:PBPs are essential for cell wall synthesisPBPS are localized on the outer face of cell wallPBPs act as carboxypeptidases and traspeptidasesAlteration in PBPs is the primary bases of resistance in MRSA  <response>: Penicillin Binding Proteins PBP catalyse an impoant step in bacterial cell wall synthesis i.e transpeptidase reaction which remove a terminal alanine in a cross linking reaction with a nearby peptide. It act as carboxy peptidase and transpeptidase. They are found in the cell membranel. Penicillin bind to this protein and inhibit its activity. Ref: Textbook of Pulmonary Medicine By D. Behera, Page 248, 252; Lippincotts Pharmacology, 4th Edition, Page 360. 