1evj
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CRYSTAL STRUCTURE OF GLUCOSE-FRUCTOSE OXIDOREDUCTASE (GFOR) DELTA1-22 S64D
OverviewOverview
N-terminal or C-terminal arms that extend from folded protein domains can, play a critical role in quaternary structure and other intermolecular, associations and/or in controlling biological activity. We have tested the, role of an extended N-terminal arm in the structure and function of a, periplasmic enzyme glucose-fructose oxidoreductase (GFOR) from Zymomonas, mobilis. We have determined the crystal structure of the NAD(+) complex of, a truncated form of the enzyme, GFORDelta, in which the first 22 residues, of the N-terminal arm of the mature protein have been deleted. The, structure, refined at 2.7 A resolution (R(cryst)=24.1%, R(free)=28.4%), shows that the truncated form of the enzyme forms a dimer and implies that, the N-terminal arm is essential for tetramer formation by wild-type GFOR., Truncation of the N-terminal arm also greatly increases the solvent, exposure of the cofactor; since GFOR activity is dependent on retention of, the cofactor during the catalytic cycle we conclude that the absence of, GFOR activity in this mutant results from dissociation of the cofactor., The N-terminal arm thus determines the quaternary structure and the, retention of the cofactor for GFOR activity and during translocation into, the periplasm. The structure of GFORDelta also shows how an additional, mutation, Ser64Asp, converts the strict NADP(+) specificity of wild-type, GFOR to a dual NADP(+)/NAD(+) specificity.
About this StructureAbout this Structure
1EVJ is a Single protein structure of sequence from Zymomonas mobilis with NAD as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of a truncated mutant of glucose-fructose oxidoreductase shows that an N-terminal arm controls tetramer formation., Lott JS, Halbig D, Baker HM, Hardman MJ, Sprenger GA, Baker EN, J Mol Biol. 2000 Dec 8;304(4):575-84. PMID:11099381
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