Gosset Molecular Classification
Peptide, Cell Wall Component
Other Names
D-Ala-D-Ala, D-alanyl-D-alanine dipeptide, Peptidoglycan precursor terminus
Disease Roles
D-alanyl-D-alanine terminus Overview
The D-alanyl-D-alanine terminus refers to the carboxy-terminal dipeptide sequence (D-Ala-D-Ala) found at the end of the stem pentapeptide in peptidoglycan precursors. This motif is a critical structural and functional element in bacterial cell wall biosynthesis, serving as a key substrate for enzymes involved in cross-linking peptidoglycan strands during cell wall assembly. It is the binding site for several antibiotics, including vancomycin and beta-lactams.
Mechanism of Action
β-lactam antibiotics inhibit penicillin-binding proteins (PBPs) that bind to the D-Ala-D-Ala motif. Glycopeptides like vancomycin bind directly to this terminus, blocking access by transpeptidases and inhibiting cell wall synthesis.
Biological Functions
Cell wall synthesis
Substrate for transpeptidases
Peptidoglycan cross-linking
Disease Associations
Bacterial infection
Safety Considerations
No safety concerns listed
Interacting Drugs
Vancomycin