4icd
From Proteopedia
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REGULATION OF ISOCITRATE DEHYDROGENASE BY PHOSPHORYLATION INVOLVES NO LONG-RANGE CONFORMATIONAL CHANGE IN THE FREE ENZYME
Overview
The structure of the phosphorylated form of isocitrate dehydrogenase from, Escherichia coli has been solved and refined to an R-factor of 16.9% at, 2.5-A resolution. Comparison with the structure of the dephosphorylated, enzyme shows that there are no large scale conformational changes and that, small conformational changes are highly localized around the site of, phosphorylation at serine 113. Tyrosine 160 rotates by 15 degrees, and, there is a local rearrangement of water structure. There is an 0.2-A net, movement of loop 230-234, and side chain shifts of 0.2 A root mean square, for isoleucine 159 and lysine 199. The lack of large conformational, changes, the observation of a possible isocitrate binding site close to, serine 113, and the demonstration that the phosphorylated enzyme is unable, to bind isocitrate suggest that this enzyme is inactivated by a direct, electrostatic interaction between the substrate and the serine phosphate.
About this Structure
4ICD is a Single protein structure of sequence from Escherichia coli with PO3 as ligand. Active as Isocitrate dehydrogenase (NADP(+)), with EC number 1.1.1.42 Full crystallographic information is available from OCA.
Reference
Regulation of isocitrate dehydrogenase by phosphorylation involves no long-range conformational change in the free enzyme., Hurley JH, Dean AM, Thorsness PE, Koshland DE Jr, Stroud RM, J Biol Chem. 1990 Mar 5;265(7):3599-602. PMID:2406256
Page seeded by OCA on Tue Nov 20 19:39:36 2007
