Members of this protein family are penicillin-binding protein 2 (PBP-2), a protein whose gene (designated pbpA or mrdA) generally is found next to the gene for RodA, a protein required for rod (bacillus) shape in many bacteria. PBP-2 acts as a transpeptidase for cell elongation (hence, rod-shape). [Cell envelope, Biosynthesis and degradation of murein sacculus and peptidoglycan]