1omp | pdb_00001omp
CRYSTALLOGRAPHIC EVIDENCE OF A LARGE LIGAND-INDUCED HINGE-TWIST MOTION BETWEEN THE TWO DOMAINS OF THE MALTODEXTRIN-BINDING PROTEIN INVOLVED IN ACTIVE TRANSPORT AND CHEMOTAXIS
|
Overview
The periplasmic maltodextrin binding protein of Escherichia coli serves as an initial receptor for the active transport of and chemotaxis toward maltooligosaccharides. The three-dimensional structure of the binding protein complexed with maltose has been previously reported [Spurlino, J. C., Lu, G.-Y., & Quiocho, F. A. (1991) J. Biol. Chem. 266, 5202-5219]. Here we report the structure of the unliganded form of the binding protein refined to 1.8-A resolution. This structure, combined with that for the liganded form, provides the first crystallographic evidence that a major ligand-induced conformational change occurs in a periplasmic binding protein. The unliganded structure shows a rigid-body "hinge-bending" between the two globular domains by approximately 35 degrees, relative to the maltose-bound structure, opening the sugar binding site groove located between the two domains. In addition, there is an 8 degrees twist of one domain relative to the other domain. The conformational changes observed between this structure and the maltose-bound structure are consistent with current models of maltose/maltodextrin transport and maltose chemotaxis and solidify a mechanism for receptor differentiation between the ligand-free and ligand-bound forms in signal transduction.
About this Structure
1OMP is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Crystallographic evidence of a large ligand-induced hinge-twist motion between the two domains of the maltodextrin binding protein involved in active transport and chemotaxis., Sharff AJ, Rodseth LE, Spurlino JC, Quiocho FA, Biochemistry. 1992 Nov 10;31(44):10657-63. PMID:1420181
Page seeded by OCA on Thu Feb 21 14:19:21 2008
