PBP1c+(pbpC)


 * __PBP1c (pbpC)__**

PBP1c is a High Molecular Mass (HMM), class A penicillin binding protein. However, its role remains ill-defined, as it is insensitive to penicillin and most other beta-lactam antibiotics, binding only specific beta-lactams. In addition, overexpression of PBP1c can't rescue the autolysis phenotype of a mutant lacking the major transpeptidases-transglycosylases PBP1a and PBP1b. An inability to record any transeptidase activity of PBP1c implies that it may function in vivo as a glycosyltransferase only.

Like other HMM PBPs, PBP1a consists of a cytoplasmic tail, a transmembrane anchor and two domains located on the outer surface of the cytoplasmic membrane joined by a beta-rich linker regions (Sauvage et al, 2008). The C-terminal penicillin binding domain of the protein possesses the transpeptidase activity, catalysing the cross-linking of peptides between two glycan strands. As a class A PBP, the N-terminal domain is responsible for the glycosytransferase activity, catalysing the elongation of uncross-linked glycan chains (Sauvage et al, 2008).
 * __Structure:__**