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1hkb
From Proteopedia
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| - | [[Image:1hkb.gif|left|200px]]<br /><applet load="1hkb" size=" | + | [[Image:1hkb.gif|left|200px]]<br /><applet load="1hkb" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1hkb, resolution 2.80Å" /> | caption="1hkb, resolution 2.80Å" /> | ||
'''CRYSTAL STRUCTURE OF RECOMBINANT HUMAN BRAIN HEXOKINASE TYPE I COMPLEXED WITH GLUCOSE AND GLUCOSE-6-PHOSPHATE'''<br /> | '''CRYSTAL STRUCTURE OF RECOMBINANT HUMAN BRAIN HEXOKINASE TYPE I COMPLEXED WITH GLUCOSE AND GLUCOSE-6-PHOSPHATE'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1HKB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=GLC: | + | 1HKB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=GLC:'>GLC</scene>, <scene name='pdbligand=G6P:'>G6P</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Hexokinase Hexokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.1 2.7.1.1] Known structural/functional Sites: <scene name='pdbsite=6CA:Glc-6-Phosphate+Binding+Site+In+C-Terminal+Domain'>6CA</scene>, <scene name='pdbsite=6CB:Glc-6-Phosphate+Binding+Site+In+C-Terminal+Domain'>6CB</scene>, <scene name='pdbsite=6NA:Glc-6-Phosphate+Binding+Site+In+N-Terminal+Domain'>6NA</scene>, <scene name='pdbsite=6NB:Glc-6-Phosphate+Binding+Site+In+N-Terminal+Domain'>6NB</scene>, <scene name='pdbsite=GCA:Glc+Binding+Site+In+C-Terminal+Domain'>GCA</scene>, <scene name='pdbsite=GCB:Glc+Binding+Site+In+C-Terminal+Domain'>GCB</scene>, <scene name='pdbsite=GNA:Glc+Binding+Site+In+N-Terminal+Domain'>GNA</scene>, <scene name='pdbsite=GNB:Glc+Binding+Site+In+N-Terminal+Domain'>GNB</scene>, <scene name='pdbsite=MCA:Metal+Ion+Binding+Site+In+C-Terminal+Domain'>MCA</scene>, <scene name='pdbsite=MCB:Metal+Ion+Binding+Site+In+C-Terminal+Domain'>MCB</scene>, <scene name='pdbsite=MNA:Metal+Ion+Binding+Site+In+N-Terminal+Domain'>MNA</scene> and <scene name='pdbsite=MNB:Metal+Ion+Binding+Site+In+N-Terminal+Domain'>MNB</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HKB OCA]. |
==Reference== | ==Reference== | ||
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[[Category: phosphotransferase]] | [[Category: phosphotransferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 09:49:49 2008'' |
Revision as of 07:49, 3 February 2008
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CRYSTAL STRUCTURE OF RECOMBINANT HUMAN BRAIN HEXOKINASE TYPE I COMPLEXED WITH GLUCOSE AND GLUCOSE-6-PHOSPHATE
Contents |
Overview
BACKGROUND: Hexokinase I is the pacemaker of glycolysis in brain tissue., The type I isozyme exhibits unique regulatory properties in that, physiological levels of phosphate relieve potent inhibition by the, product, glucose-6-phosphate (Gluc-6-P). The 100 kDa polypeptide chain of, hexokinase I consists of a C-terminal (catalytic) domain and an N-terminal, (regulatory) domain. Structures of ligated hexokinase I should provide a, basis for understanding mechanisms of catalysis and regulation at an, atomic level. RESULTS: The complex of human hexokinase I with glucose and, Gluc-6-P (determined to 2.8 A resolution) is a dimer with twofold, molecular symmetry. The N- and C-terminal domains of one monomer interact, with the C- and N-terminal domains, respectively, of the symmetry-related, monomer. The two domains of a monomer are connected by a single alpha, helix and each have the fold of yeast hexokinase. Salt links between a, possible cation-binding loop of the N-terminal domain and a loop of the, C-terminal domain may be important to regulation. Each domain binds single, glucose and Gluc-6-P molecules in proximity to each other. The, 6-phosphoryl group of bound Gluc-6-P at the C-terminal domain occupies the, putative binding site for ATP, whereas the 6-phosphoryl group at the, N-terminal domain may overlap the binding site for phosphate. CONCLUSIONS:, The binding synergism of glucose and Gluc-6-P probably arises out of the, mutual stabilization of a common (glucose-bound) conformation of, hexokinase I. Conformational changes in the N-terminal domain in response, to glucose, phosphate, and/or Gluc-6-P may influence the binding of ATP to, the C-terminal domain.
Disease
Known disease associated with this structure: Hemolytic anemia due to hexokinase deficiency OMIM:[142600]
About this Structure
1HKB is a Single protein structure of sequence from Homo sapiens with , and as ligands. Active as Hexokinase, with EC number 2.7.1.1 Known structural/functional Sites: , , , , , , , , , , and . Full crystallographic information is available from OCA.
Reference
The mechanism of regulation of hexokinase: new insights from the crystal structure of recombinant human brain hexokinase complexed with glucose and glucose-6-phosphate., Aleshin AE, Zeng C, Bourenkov GP, Bartunik HD, Fromm HJ, Honzatko RB, Structure. 1998 Jan 15;6(1):39-50. PMID:9493266
Page seeded by OCA on Sun Feb 3 09:49:49 2008
Categories: Hexokinase | Homo sapiens | Single protein | Aleshin, A.E. | Bartunik, H.D. | Burenkov, G.P. | Fromm, H.J. | Honzatko, R.B. | Zeng, C. | CA | G6P | GLC | Allosteric enzyme | Glucose | Glucose-6-phosphate | Glycolysis | Phosphotransferase
