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Phosphorylation of C6- and C3-positions of glucosyl residues in starch is catalysed by distinct dikinases
- Glucan, water dikinase (GWD) and phosphoglucan, water dikinase (PWD) are required for normal starch metabolism. We analysed starch phosphorylation in Arabidopsis wildtype plants and mutants lacking either GWD or PWD using P-31 NMR. Phosphorylation at both C6- and C3-positions of glucose moieties in starch was drastically decreased in GWD-deficient mutants. In starch from PWD-deficient plants C3-bound phosphate was reduced to levels close to the detection limit. The latter result contrasts with previous reports according to which GWD phosphorylates both C6- and C3-positions. In these studies, phosphorylation had been analysed by HPLC of acid-hydrolysed glucans. We now show that maltose-6-phosphate, a product of incomplete starch hydrolysis, co-eluted with glucose-3-phosphate under the chromatographic conditions applied. Re-examination of the specificity of the dikinases using an improved method demonstrates that C6- and C3-phosphorylation is selectively catalysed by GWD and PWD, respectively.
Author details: | Gerhard RitteGND, Matthias HeydenreichORCiD, Sebastian MahlowGND, Sophie Haebel, Oliver KoettingGND, Martin SteupORCiDGND |
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DOI: | https://doi.org/10.1016/j.febslet.2006.07.085 |
ISSN: | 0014-5793 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/16914145 |
Title of parent work (English): | FEBS letters : the journal for rapid publication of short reports in molecular biosciences |
Publisher: | Elsevier |
Place of publishing: | Amsterdam |
Publication type: | Article |
Language: | English |
Date of first publication: | 2006/08/10 |
Publication year: | 2006 |
Release date: | 2020/05/28 |
Tag: | GWD; P-31 NMR; PWD; starch phosphorylation |
Volume: | 580 |
Issue: | 20 |
Number of pages: | 5 |
First page: | 4872 |
Last Page: | 4876 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Biochemie und Biologie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie |
Peer review: | Referiert |