argininosuccinate synthase. argG in bacteria, ARG1 in Saccharomyces cerevisiae. There is a very unusual clustering in the alignment, with a deep split between one cohort of E. coli, H. influenzae, and Streptomyces, and the other cohort of eukaryotes, archaea, and the rest of the eubacteria [Amino acid biosynthesis, Glutamate family].

This family is most closely related to the GT1 family of glycosyltransferases and named after YqgM in Bacillus licheniformis about which little is known. Glycosyltransferases catalyze the transfer of sugar moieties from activated donor molecules to specific acceptor molecules, forming glycosidic bonds. The acceptor molecule can be a lipid, a protein, a heterocyclic compound, or another carbohydrate residue. This group of glycosyltransferases is most closely related to the previously defined glycosyltransferase family 1 (GT1). The members of this family may transfer UDP, ADP, GDP, or CMP linked sugars. The diverse enzymatic activities among members of this family reflect a wide range of biological functions. The protein structure available for this family has the GTB topology, one of the two protein topologies observed for nucleotide-sugar-dependent glycosyltransferases. GTB proteins have distinct N- and C- terminal domains each containing a typical Rossmann fold. The two domains have high structural homology despite minimal sequence homology. The large cleft that separates the two domains includes the catalytic center and permits a high degree of flexibility. The members of this family are found mainly in certain bacteria and archaea.

Glycosyltransferase [Cell envelope biogenesis, outer membrane]

transferase, transferring glycosyl groups

This family is most closely related to the GT1 family of glycosyltransferases. The yeast gene ALG1 has been shown to function as a mannosyltransferase that catalyzes the formation of dolichol pyrophosphate (Dol-PP)-GlcNAc2Man from GDP-Man and Dol-PP-Glc-NAc2, and participates in the formation of the lipid-linked precursor oligosaccharide for N-glycosylation. In humans ALG1 has been associated with the congenital disorders of glycosylation (CDG) designated as subtype CDG-Ik.