2ae2

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Revision as of 05:57, 21 November 2007

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spinqualitylabelsall models 2ae2, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

TROPINONE REDUCTASE-II COMPLEXED WITH NADP+ AND PSEUDOTROPINE

Overview

Tropinone reductase-II (TR-II) catalyzes the NADPH-dependent reduction of, the carbonyl group of tropinone to a beta-hydroxyl group. The crystal, structure of TR-II complexed with NADP+ and pseudotropine (psi-tropine), has been determined at 1.9 A resolution. A seven-residue peptide near the, active site, disordered in the unliganded structure, is fixed in the, ternary complex by participation of the cofactor and substrate binding., The psi-tropine molecule is bound in an orientation which satisfies the, product configuration and the stereochemical arrangement toward the, cofactor. The substrate binding site displays a complementarity to the, bound substrate (psi-tropine) in its correct orientation. In addition, electrostatic interactions between the substrate and Glu156 seem to, specify the binding position and orientation of the substrate. A, comparison between the active sites in TR-II and TR-I shows that they, provide different van der Waals surfaces and electrostatic features. These, differences likely contribute to the correct binding mode of the, substrates, which are in opposite orientations in TR-II and TR-I, and to, different reaction stereospecificities. The active site structure in the, TR-II ternary complex also suggests that the arrangement of the substrate, cofactor, and catalytic residues is stereoelectronically favorable for the, reaction.

About this Structure

2AE2 is a Single protein structure of sequence from Datura stramonium with NAP and PTO as ligands. Active as Tropinone reductase II, with EC number 1.1.1.236 Full crystallographic information is available from OCA.

Reference

Structure of tropinone reductase-II complexed with NADP+ and pseudotropine at 1.9 A resolution: implication for stereospecific substrate binding and catalysis., Yamashita A, Kato H, Wakatsuki S, Tomizaki T, Nakatsu T, Nakajima K, Hashimoto T, Yamada Y, Oda J, Biochemistry. 1999 Jun 15;38(24):7630-7. PMID:10387002

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