Abstract

D-Alanine:D-Alanine ligase (DDl) catalyzes the formation of D-Alanine:D-Alanine dipeptide and is an essential enzyme in bacterial cell wall biosynthesis. This enzyme does not have a human ortholog, making it an attractive target for developing new antibiotic drugs. We determined the crystal structure at 2.23 Å resolution of DDl from Streptococcus mutans (SmDDl), the principal aetiological agent of human dental caries. This structure reveals that SmDDl is a dimer and has a disordered ω-loop region.

Keywords: X-ray crystal structure, amino acids and peptides, DDl, Streptococcus mutans