Galactokinase, glycosyltransferase <p>Members of this family are predicted to be bifunctional enzymes. </p> <p>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).</p> <p>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) [<cite idref="PUB00015675"/>]. 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 [<cite idref="PUB00015644"/>]. 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 [<cite idref="PUB00015644"/>]. 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 [<cite idref="PUB00015835"/>, <cite idref="PUB00015644"/>, <cite idref="PUB00015669"/>, <cite idref="PUB00015730"/>].</p> <p>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.</p>