| Type: | Family | Name: | Galactokinase, glycosyltransferase |
| Description: | Members of this family are predicted to be bifunctional enzymes. Their C-terminal domain belongs to the GHMP kinase domain superfamily. Based on sequence similarity, it is predicted to be galactokinases (a subgroup of GHMP kinases).GHMP kinases are a unique class of ATP-dependent enzymes (the abbreviation of which refers to the original members: galactokinase, homoserine kinase, mevalonate kinase, and phosphomevalonate kinase) []. Enzymes belonging to this superfamily contain three well-conserved motifs, the second of which has the typical sequence Pro-X-X-X-Gly-Leu-X-Ser-Ser-Ala and is involved in ATP binding []. The phosphate binding loop in GHMP kinases is distinct from the classical P-loops found in many ATP/GTP binding proteins. The bound ADP molecule adopts a rare syn conformation and is in the opposite orientation from those bound to the P-loop-containing proteins []. GHMP kinases display a distinctly bilobal appearance with their N-terminal subdomains dominated by a mixed beta-sheet flanked on one side by alpha-helices and their C-terminal subdomains containing a four stranded anti-parallel beta-sheet [, , , ].The domain in the N-terminal region belongs to the UDP-glycosyltransferase/glycogen phosphorylase SCOP domain superfamily (as detected by SMART), and to the glycosyltransferase family according to PSI-BLAST analysis. The exact function of this particular variety of this domain is unknown. | Short Name: | Galk_glycosyltransferase |
