1hyh
From Proteopedia
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| , resolution 2.2Å | |||||||
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| Ligands: | and | ||||||
| Activity: | L-lactate dehydrogenase, with EC number 1.1.1.27 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF L-2-HYDROXYISOCAPROATE DEHYDROGENASE FROM LACTOBACILLUS CONFUSUS AT 2.2 ANGSTROMS RESOLUTION-AN EXAMPLE OF STRONG ASYMMETRY BETWEEN SUBUNITS
Overview
L-2-Hydroxyisocaproate dehydrogenase (L-HicDH) from Lactobacillus confusus, a homotetramer with a molecular mass of 33 kDa per subunit, belongs to the protein family of the NAD(+)-dependent L-2-hydroxycarboxylate dehydrogenases. L-HicDH was crystallized with ammonium sulphate as precipitant in the presence of NAD+. The crystals belong to the trigonal space group P3(2)21, with a = 135.9 A and c = 205.9 A, and diffract X-rays to 2.2 A resolution. The crystal structure was solved by Patterson search and molecular replacement techniques and refined to an R-value of 21.4% (2.2 to 8 A). The final structure model contains one NAD+ molecule and one sulphate ion per subunit, with 309 water molecules. An unusual feature of this crystal structure is the deviation of the protein subunits from non-crystallographic symmetry, which is so strong that it can be detected globally by self-rotation calculations in reciprocal space. This asymmetry is especially pronounced in the environment of the active site; it is reflected also in the nicotinamide conformation of NAD+ and allows some conclusions to be drawn about the catalytic mechanism. In this context, an "inner active site loop" is identified as a structural element of fundamental functional importance. Furthermore, with knowledge of the crystal structure of L-HicDH the differences in substrate specificity between L-HicDH and the L-lactate dehydrogenases can be partly explained.
About this Structure
1HYH is a Single protein structure of sequence from Weissella confusa. Full crystallographic information is available from OCA.
Reference
Crystal structure of L-2-hydroxyisocaproate dehydrogenase from Lactobacillus confusus at 2.2 A resolution. An example of strong asymmetry between subunits., Niefind K, Hecht HJ, Schomburg D, J Mol Biol. 1995 Aug 11;251(2):256-81. PMID:7643402
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