| EC |
2.7.9.5 |
| Accepted name: |
phosphoglucan, water dikinase |
| Reaction: |
ATP + [phospho-α-glucan] + H2O = AMP + O-phospho-[phospho-α-glucan] + phosphate |
| Other name(s): |
PWD; OK1 |
| Systematic name: |
ATP:phospho-α-glucan, water phosphotransferase |
| Comments: |
The enzyme phosphorylates granular starch that has previously been phosphorylated by EC 2.7.9.4, 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 [1]. In contrast to EC 2.7.9.4, which phosphorylates glucose groups in glucans on O-6, this enzyme phosphorylates glucose groups in phosphorylated starch on O-3 [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: 912567-76-1 |
| References: |
| 1. |
Kötting, O., Pusch, K., Tiessen, A., Geigenberger, P., Steup, M. and Ritte, G. Identification of a novel enzyme required for starch metabolism in Arabidopsis leaves. The phosphoglucan, water dikinase. Plant Physiol. 137 (2005) 242–252. [DOI] [PMID: 15618411] |
| 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. [DOI] [PMID: 16914145] |
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| [EC 2.7.9.5 created 2005] |
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