Sandbox Reserved 552
| This Sandbox is Reserved from 05/22/2012, through 07/22/2012 for use in the course "BIOL 414" taught by Greg Buhrman at the North Carolina State University, Raleigh, NC USA. This reservation includes Sandbox Reserved 551 through Sandbox Reserved 590. |
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Hi Alex, Here is your very own proteopedia page for pdb code: 1HKB. Your presentation date is scheduled for: June 8. Have Fun!
Greg Buhrman
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| 1hkb, 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 | ||||||||
CRYSTAL STRUCTURE OF RECOMBINANT HUMAN BRAIN HEXOKINASE TYPE I COMPLEXED WITH GLUCOSE AND GLUCOSE-6-PHOSPHATECRYSTAL STRUCTURE OF RECOMBINANT HUMAN BRAIN HEXOKINASE TYPE I COMPLEXED WITH GLUCOSE AND GLUCOSE-6-PHOSPHATE
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.
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
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this StructureAbout this Structure
1HKB is a 2 chains structure with sequences from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
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