1mgy
From Proteopedia
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Structure of the D85S mutant of bacteriorhodopsin with bromide bound
Overview
We report the crystal structure of a bromide-bound form of the D85S mutant of bacteriorhodopsin, bR(D85S), a protein that uses light energy rather than ATP to pump halide ions across the cell membrane. Comparison of the structure of the halide-bound and halide-free states reveals that both displacements of individual side-chain positions and concerted helical movements occur on the extracellular side of the protein. Analysis of these structural changes reveals how this ion pump first facilitates ion uptake deep within the cell membrane and then prevents the backward escape of ions later in the pumping cycle. Together with the information provided by structures of intermediate states in the bacteriorhodopsin photocycle, this study also suggests the overall design principles that are necessary for ion pumping.
About this Structure
1MGY is a Single protein structure of sequence from Halobacterium salinarum with , , and as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of the bromide-bound D85S mutant of bacteriorhodopsin: principles of ion pumping., Facciotti MT, Cheung VS, Nguyen D, Rouhani S, Glaeser RM, Biophys J. 2003 Jul;85(1):451-8. PMID:12829500
Page seeded by OCA on Thu Feb 21 13:55:03 2008
Categories: Halobacterium salinarum | Single protein | Cheung, V S. | Facciotti, M T. | Glaeser, R M. | Nguyen, D. | Rouhani, S. | BR | K | LI1 | RET | Anion | Bacteriorhodopsin | Bromide | Halide | Pump
