Dolichyl-phosphate-mannose-protein mannosyltransferase. This is a family of Dolichyl-phosphate-mannose-protein mannosyltransferase proteins EC:2.4.1.109. These proteins are responsible for O-linked glycosylation of proteins, they catalyze the reaction:- Dolichyl phosphate D-mannose + protein <=> dolichyl phosphate + O-D-mannosyl-protein. Also in this family is Drosophila rotated abdomen protein which is a putative mannosyltransferase. This family appears to be distantly related to pfam02516 (A Bateman pers. obs.). This family also contains sequences from ArnTs (4-amino-4-deoxy-L-arabinose lipid A transferase). They catalyze the addition of 4-amino-4-deoxy-l-arabinose (l-Ara4N) to the lipid A moiety of the lipopolysaccharide. This is a critical modification enabling bacteria (e.g. Escherichia coli and Salmonella typhimurium) to resist killing by antimicrobial peptides such as polymyxins. Members such as undecaprenyl phosphate-alpha-4-amino-4-deoxy-L-arabinose arabinosyl transferase are predicted to have 12 trans-membrane regions. The N-terminal portion of these proteins is hypothesized to have a conserved glycosylation activity which is shared between distantly related oligosaccharyltransferases ArnT and PglB families.
Alg9-like mannosyltransferase family. Members of this family are mannosyltransferase enzymes. At least some members are localized in endoplasmic reticulum and involved in GPI anchor biosynthesis.
CrystalStructure of ArnT from Cupriavidus metallidurans in the apo state [Cupriavidus metallidurans CH34],5F15_A Crystal Structure of ArnT from Cupriavidus metallidurans bound to Undecaprenyl phosphate [Cupriavidus metallidurans CH34]