The enzyme catalyzes the phosphorylation of a single serine residue, thereby converting inactive phosphorylase b to active glycogen phosphorylase a and stimulating glycogen degradation (PMID10545198). It is composed of four types of subunits (alpha, beta, gamma, delta). The gamma subunit is the catalytic one and has two metal binding sites (PMID9362479).
CATALYTIC METAL(S)
| Metal/Site Information | |||||
| Residue in MACiE* | Atom in MACiE* | Residue Type in MACiE | Physiological Metal |
Site Type |
Function(s) |
| MN 382 x | MN | magnesium | magnesium/manganese | mononuclear | Coordinates substrate Electrostatic stabiliser Increases electrophilicity |
| MN 383 x | MN | none | magnesium/manganese | mononuclear | - |
*It refers to the MACiE reference pdb: 2phk
| Metal/s Properties in Resting State | ||||||
| MN 382 x | Resting state enzyme (-) | |||||
| Oxidation State | 2 | |||||
| Coordination Geometry | unknownGeometry | |||||
| Coordination Number | unknown | |||||
| Notes | - | |||||
| MN 383 x | Resting state enzyme (-) | |||||
| Oxidation State | 2 | |||||
| Coordination Geometry | unknownGeometry | |||||
| Coordination Number | unknown | |||||
| Notes | - | |||||
| References |
| -Lowe ED, Noble ME, Skamnaki VT, Oikonomakos NG, Owen DJ, Johnson LN The crystal structure of a phosphorylase kinase peptide substrate complex: kinase substrate recognition. EMBO J. 1997 Nov 17;16(22):6646-58.(MEDLINE:9362479) |
| -Owen DJ, Noble ME, Garman EF, Papageorgiou AC, Johnson LN Two structures of the catalytic domain of phosphorylase kinase: an active protein kinase complexed with substrate analogue and product. Structure. 1995 May 15;3(5):467-82.(MEDLINE:7663944) |
| - Some information have been also deduced from the MACiE mechanism model |