IUBMB Enzyme Nomenclature


Accepted name: α-glucan, water dikinase

Reaction: ATP + α-glucan + H2O = AMP + phospho-α-glucan + phosphate

Other name(s): starch-related R1 protein; GWD

Systematic name: ATP:α-glucan, water phosphotransferase

Comments: Requires Mg2+. ATP appears to be the only phosphate donor. No activity could be detected using GTP, UTP, phosphoenolpyruvate or diphosphate [1]. The protein phosphorylates glucans exclusively at the O-6 position of glucosyl residues [2]. The protein phosphorylates itself with the β-phosphate of ATP, which is then transferred to the glucan [1].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 664327-94-0


1. Ritte, G., Lloyd, J.R., Eckermann, N., Rottmann, A., Kossmann, J. and Steup, M. The starch-related R1 protein is an α-glucan, water dikinase. Proc. Natl. Acad. Sci. USA 99 (2002) 7166-7171. [PMID: 12011472]

2. Ritte, G., Heydenreich, M., Mahlow, S., Haebel, S., Kötting, O. and Steup, M. Phosphorylation of C6- and C3-positions of glucosyl residues in starch is catalysed by distinct dikinases. FEBS Lett. 580 (2006) 4872-4876. [PMID: 16914145]

[EC created 2002]

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