D-Ala-D-Ala dipeptidase/D-Ala-D-Ala carboxypeptidase (VanXYc) and related proteins
VanXYc peptidase (also known as vanXY(C) peptidase, D-alanyl-D-alanine carboxypeptidase D,D-dipeptidase/D,D-carboxypeptidase, vancomycin resistance D,D-dipeptidase) is a Zn2+-dependent enzyme that mediates resistance to the antibiotic vancomycin in Enterococci. Some of the vancomycin resistance operons encode VanXY D,D-carboxypeptidase which hydrolyzes both, dipeptide (D-Ala-D-Ala) or pentapeptide (UDP-MurNac-L-Ala-D-Glu-L-Lys-D-Ala-D-Ala). It is a bifunctional enzyme that catalyzes D,D-peptidase and D,D-carboxypeptidase activities. VanXY has higher sequence similarity to VanY than with VanX and hydrolyzes D,D-dipeptides such as D-Ala-D-Ala, whereas VanY is inactive against this substrate; thus having a less restrictive active site to accommodate larger substrates such as UDP-MurNAc-pentapeptide[Ala]. This family belongs to the MEROPS family M15, subfamily B, and includes the D,D-dipeptidases VanXYg and VanXYe.
Jiyao W et al.(2023). "The conserved domain database in 2023.",