1dr8
From Proteopedia
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STRUCTURE OF MODIFIED 3-ISOPROPYLMALATE DEHYDROGENASE AT THE C-TERMINUS, HD177
Overview
Thermal stability of the Thermus thermophilus isopropylmalate, dehydrogenase enzyme was substantially lost upon the deletion of three, residues from the C-terminus. However, the stability was partly recovered, by the addition of two, four and seven amino acid residues (called HD177, HD708 and HD711, respectively) to the C-terminal region of the truncated, enzyme. Three structures of these mutant enzymes were determined by an, X-ray diffraction method. All protein crystals belong to space group P2(1), and their structures were solved by a standard molecular replacement, method where the original dimer structure of the A172L mutant was used as, a search model. Thermal stability of these mutant enzymes is discussed, based on the 3D structure with special attention to the width of the, active-site groove and the minor groove, distortion of beta-sheet pillar, structure and size of cavity in the domain-domain interface around the, C-terminus. Our previous studies revealed that the thermal stability of, isopropylmalate dehydrogenase increases when the active-site cleft is, closed (the closed form). In the present study it is shown that the, active-site cleft can be regulated by open-close movement of the minor, groove located at the opposite side to the active-site groove on the same, subunit, through a paperclip-like motion.
About this Structure
1DR8 is a Single protein structure of sequence from Thermus thermophilus. Active as 3-isopropylmalate dehydrogenase, with EC number 1.1.1.85 Full crystallographic information is available from OCA.
Reference
Crystal structures of 3-isopropylmalate dehydrogenases with mutations at the C-terminus: crystallographic analyses of structure-stability relationships., Nurachman Z, Akanuma S, Sato T, Oshima T, Tanaka N, Protein Eng. 2000 Apr;13(4):253-8. PMID:10810156
Page seeded by OCA on Tue Nov 20 13:31:13 2007
