Reaction: GDP-β-L-colitose + β-D-galactopyranosyl-(1→3)-N-acetyl-D-glucosamine = GDP + α-L-colitosyl-(1→2)-β-D-galactosyl-(1→3)-N-acetyl-D-glucosamine
Glossary: β-D-galactopyranosyl-(1→3)-N-acetyl-D-glucosamine = lacto-N-biose
Other name(s): wbgN (gene name)
Systematic name: GDP-β-L-colitose:β-D-galactopyranosyl-(1→3)-N-acetyl-D-glucosamine L-colitosyltransferase (configuration-inverting)
Comments: The enzyme, characterized from the bacterium Escherichia coli O55:H7, participates in the biosynthesis of an O-antigen. The reaction involves anomeric inversion, and does not require any metal ions. The enzyme is highly specific towards the acceptor, exclusively recognizing lacto-N-biose, but can accept GDP-L-fucose as the donor with almost the same activity as with GDP-β-L-colitose.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
1. Wu, Z., Zhao, G., Li, T., Qu, J., Guan, W., Wang, J., Ma, C., Li, X., Zhao, W., Wang, P.G. and Li, L. Biochemical characterization of an α1,2-colitosyltransferase from Escherichia coli O55:H7. Glycobiology (2015) . [PMID: 26703456]