Abstract | BACKGROUND:
Galactokinase catalyses the first committed step of galactose catabolism in which the sugar is phosphorylated at the expense of MgATP. Recent structural studies suggest that the enzyme makes several contacts with galactose--five side chain and two main chain hydrogen bonds. Furthermore, it has been suggested that inhibition of galactokinase may help sufferers of the genetic disease classical galactosemia which is caused by defects in another enzyme of the pathway galactose-1-phosphate uridyl transferase. Galactokinases from different sources have a range of substrate specificities and a diversity of kinetic mechanisms. Therefore only studies on the human enzyme are likely to be of value in the design of therapeutically useful inhibitors. RESULTS: CONCLUSIONS: The enzyme is tolerant to small changes at position 2 of the sugar ring, but not at positions 4 and 6. The results from site directed mutagenesis could not have been predicted from the crystal structure alone and needed to be determined experimentally.
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Authors | David J Timson, Richard J Reece |
Journal | BMC biochemistry
(BMC Biochem)
Vol. 4
Pg. 16
(Nov 04 2003)
ISSN: 1471-2091 [Electronic] England |
PMID | 14596685
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Arabidopsis Proteins
- Carbohydrates
- Aspartic Acid
- Glutamic Acid
- Phosphotransferases (Alcohol Group Acceptor)
- ARA1 protein, Arabidopsis
- Galactokinase
- Alanine
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Topics |
- Alanine
(genetics)
- Arabidopsis Proteins
(chemistry)
- Aspartic Acid
(genetics)
- Binding Sites
- Carbohydrate Metabolism
- Carbohydrates
(chemistry)
- Galactokinase
(chemistry, genetics, metabolism)
- Glutamic Acid
(genetics)
- Humans
- Kinetics
- Mutation
- Phosphotransferases (Alcohol Group Acceptor)
(chemistry)
- Solubility
- Substrate Specificity
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