Penicillin-binding protein

Function

Penicillin-binding proteins (PBPs) are a group of proteins that are characterized by their affinity for and binding of penicillin. They are a normal constituent of many bacteria; the name just reflects the way by which the protein was discovered. All β-lactam antibiotics (except for tabtoxinine-β-lactam, which inhibits glutamine synthetase) bind to PBPs, which are essential for bacterial cell wall synthesis. PBPs are members of a subgroup of enzymes called transpeptidases. Specifically, PBPs are DD-transpeptidases. See also Penicillin-binding proteins.

Penicillin-binding protein or peptidoglycan d,d-transpeptidase or D-alanyl-D-alanine carboxypeptidase (PBP) is a bacterial protein which binds antibiotics. There are several PBPs in each organism. PBPs are involved in the synthesis of bacterial cell wall^[1]. The PBP are classified to high-molecular weight and low-molecular weight groups. PBP 3 is also named FtsI.

See also:

• DD-transpeptidase (Hebrew).
• Penicillin-binding proteins and antibiotics

For Mycobacterium tuberculosis PBP complex with penicillin see Mycobacterium Tuberculosis Transpeptidase Domain.

Relevance

PBP inhibition by antibiotics leads to irregularities in the cell wall and eventual bacterial death^[2].

See also How B-lactam drugs work.

Structural highlights

E. coli PBP structure shows a distinct . The contains the ^[3]. Water molecules are shown as red spheres.

3D structures of penicillin-binding protein

Penicillin-binding protein 3D structures