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1hkc
From Proteopedia
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[[Image:1hkc.gif|left|200px]] | [[Image:1hkc.gif|left|200px]] | ||
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'''RECOMBINANT HUMAN HEXOKINASE TYPE I COMPLEXED WITH GLUCOSE AND PHOSPHATE''' | '''RECOMBINANT HUMAN HEXOKINASE TYPE I COMPLEXED WITH GLUCOSE AND PHOSPHATE''' | ||
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[[Category: Aleshin, A E.]] | [[Category: Aleshin, A E.]] | ||
[[Category: Honzatko, R B.]] | [[Category: Honzatko, R B.]] | ||
| - | [[Category: | + | [[Category: Allosteric enzyme]] |
| - | [[Category: | + | [[Category: Glucose]] |
| - | [[Category: | + | [[Category: Glycolysis]] |
| - | [[Category: | + | [[Category: Phosphate]] |
| - | [[Category: | + | [[Category: Phosphotransferase]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 18:56:25 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 15:56, 2 May 2008
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| 1hkc, resolution 2.80Å () | |||||||||
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| Ligands: | , , | ||||||||
| Activity: | Hexokinase, with EC number 2.7.1.1 | ||||||||
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| Resources: | FirstGlance, OCA, RCSB, PDBsum | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
RECOMBINANT HUMAN HEXOKINASE TYPE I COMPLEXED WITH GLUCOSE AND PHOSPHATE
Overview
Hexokinase I, the pacemaker of glycolysis in brain tissue and red blood cells, is comprised of two similar domains fused into a single polypeptide chain. The C-terminal half of hexokinase I is catalytically active, whereas the N-terminal half is necessary for the relief of product inhibition by phosphate. A crystalline complex of recombinant human hexokinase I with glucose and phosphate (2.8 A resolution) reveals a single binding site for phosphate and glucose at the N-terminal half of the enzyme. Glucose and phosphate stabilize the N-terminal half in a closed conformation. Unexpectedly, glucose binds weakly to the C-terminal half of the enzyme and does not by itself stabilize a closed conformation. Evidently a stable, closed C-terminal half requires either ATP or glucose 6-phosphate along with glucose. The crystal structure here, in conjunction with other studies in crystallography and directed mutation, puts the phosphate regulatory site at the N-terminal half, the site of potent product inhibition at the C-terminal half, and a secondary site for the weak interaction of glucose 6-phosphate at the N-terminal half of the enzyme. The relevance of crystal structures of hexokinase I to the properties of monomeric hexokinase I and oligomers of hexokinase I bound to the surface of mitochondria is discussed.
About this Structure
1HKC is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Regulation of hexokinase I: crystal structure of recombinant human brain hexokinase complexed with glucose and phosphate., Aleshin AE, Zeng C, Bartunik HD, Fromm HJ, Honzatko RB, J Mol Biol. 1998 Sep 18;282(2):345-57. PMID:9735292 Page seeded by OCA on Fri May 2 18:56:25 2008
