EC 18.104.22.168 - Phosphoglucan, water dikinase
IntEnz Enzyme Nomenclature
- ATP + [phospho-alpha-glucan] + H2O = AMP + O-phospho-[phospho-alpha-glucan] + phosphate
The enzyme phosphorylates granular starch that has previously been phosphorylated by EC 22.214.171.124, α-glucan, water dikinase; there is no activity with unphosphorylated glucans. It transfers the β-phosphate of ATP to the phosphoglucan, whereas the γ-phosphate is transferred to water . In contrast to EC 126.96.36.199, which phosphorylates the glucose groups in glucans predominantly on O-6, this enzyme phosphorylates glucose groups in phosphorylated starch predominantly on O-3 . The protein phosphorylates itself with the β-phosphate of ATP, which is then transferred to the glucan .
Links to other databases
Identification of a novel enzyme required for starch metabolism in Arabidopsis leaves. The phosphoglucan, water dikinase.Plant Physiol. 137 : 242-252 (2005). [PMID: 15618411]
Phosphorylation of C6- and C3-positions of glucosyl residues in starch is catalysed by distinct dikinases.FEBS Lett. 580 : 4872-4876 (2006). [PMID: 16914145]
[EC 188.8.131.52 created 2005]