Glycogenin
| glycogenin glucosyltransferase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
Glycogenin structure (from rabbit). | |||||||||
| Identifiers | |||||||||
| EC no. | 2.4.1.186 | ||||||||
| CAS no. | 117590-73-5 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Glycogenin is an enzyme involved in converting glucose to glycogen. It acts as a primer, by polymerizing the first few glucose molecules, after which other enzymes take over. It is a homodimer of 37-kDa subunits and is classified as a glycosyltransferase.
It catalyzes the chemical reactions:
- UDP-alpha-D-glucose + glycogenin ⇌ UDP + alpha-D-glucosylglycogenin
- UDP-alpha-D-glucose + a glucosyl-glycogenin ⇌ (1,4-alpha-D-glucosyl)n-glucosyl glucogenin + UDP + H+
Thus, the two substrates of this enzyme are UDP-alpha-D-glucose and glycogenin, whereas its two products are UDP and alpha-D-glucosylglycogenin.