Penicillin-binding proteins (PBPs) function in the late steps of murein biosynthesis. Penicillin Binding Protein 2X is a membrane bound transpeptidase belong to the high molecular weight class B group of penicillin binding proteins. This enzyme is one of the primary targets of betalactam antibiotics in Streptococcus pneumoniae. Betalactams inactivate the PBPs by acylating an essential serine residue in the active site of these proteins.
