2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase-like protein; Cytidylyltransferase required for protein O-linked mannosylation. Catalyzes the formation of CDP- ribitol nucleotide sugar from D-ribitol 5-phosphate. CDP-ribitol is a substrate of FKTN during the biosynthesis of the phosphorylated O-mannosyl trisaccharide (N-acetylgalactosamine-beta-3-N-acetylglucosamine- beta-4-(phosphate-6-)mannose), a carbohydrate structure present in alpha-dystroglycan (DAG1), which is required for binding laminin G-like domain-containing extracellular proteins with high affinity. Shows activity toward other pentose phosphate sugars and mediates formation of CDP-ribulose or CDP-ribose using CTP and ribulose-5-phosphate or ribose-5- phosphate, respectively. Not Involved in dolichol production.
Synonyms: ISPD, A4D126, A4D126p, hA4D126, 184.108.40.206 ...