Till sidans topp

Sidansvarig: Webbredaktion
Sidan uppdaterades: 2012-09-11 15:12

Tipsa en vän
Utskriftsversion

Bacteriorhodopsin: Would … - Göteborgs universitet Till startsida
Webbkarta
Till innehåll Läs mer om hur kakor används på gu.se

Bacteriorhodopsin: Would the real structural intermediates please stand up?

Artikel i vetenskaplig tidskrift
Författare Cecilia Wickstrand
Robert Dods
A. Royant
Richard Neutze
Publicerad i Biochimica Et Biophysica Acta-General Subjects
Volym 1850
Nummer/häfte 3
Sidor 536-553
ISSN 0304-4165
Publiceringsår 2015
Publicerad vid Institutionen för kemi och molekylärbiologi
Sidor 536-553
Språk en
Länkar dx.doi.org/10.1016/j.bbagen.2014.05...
Ämnesord Bacteriorhodopsin, Structural intermediates, Proton pumping, Global structural analysis, X-RAY-STRUCTURE, CRYSTALLIZING MEMBRANE-PROTEINS, VECTORIAL PROTON, TRANSPORT, 2.3 ANGSTROM RESOLUTION, LIPIDIC CUBIC PHASES, RADIATION-DAMAGE, CONFORMATIONAL-CHANGES, SCHIFF-BASE, CRYSTALLOGRAPHIC, STRUCTURE, ELECTRON CRYSTALLOGRAPHY, Biochemistry & Molecular Biology, Biophysics
Ämneskategorier Biokemi och molekylärbiologi, Biofysik

Sammanfattning

Background: Bacteriorhodopsin (bR) is the simplest known light driven proton pump and has been heavily studied using structural methods: eighty four X-ray diffraction, six electron diffraction and three NMR structures of bR are deposited within the protein data bank. Twenty one X-ray structures report light induced structural changes and changes induced by mutation, changes in pH, thermal annealing or X-ray induced photoreduction have also been examined. Scope of review: We argue that light-induced structural changes that are replicated across several studies by independent research groups are those most likely to represent what is happening in reality. We present both internal distance matrix analyses that sort deposited bR structures into hierarchal trees, and difference Fourier analysis of deposited X-ray diffraction data. Major conclusions: An internal distance matrix analysis separates most wild-type bR structures according to their different crystal forms, indicating how the protein's structure is influenced by crystallization conditions. A similar analysis clusters eleven studies of illuminated bR crystals as one branch of a hierarchal tree with reproducible movements of the extracellular portion of helix C towards helix G, and of the cytoplasmic portion of helix F away from helices A, B and G. All crystallographic data deposited for illuminated crystals show negative difference density on a water molecule (Wat402) that forms H-bonds to the retinal Schiff Base and two aspartate residues (Asp85, Asp212) in the bR resting state. Other recurring difference density features indicated reproducible side-chain, backbone and water molecule displacements. X-ray induced radiation damage also disorders Wat402 but acts via cleaving the head-groups of Asp85 and Asp212. General significance: A remarkable level of agreement exists when deposited structures and crystallographic observations are viewed as a whole. From this agreement a unified picture of the structural mechanism of light-induced proton pumping by bR emerges. This article is part of a Special Issue entitled Structural biochemistry and biophysics of membrane proteins. (C) 2014 The Authors. Published by Elsevier B.V.

Sidansvarig: Webbredaktion|Sidan uppdaterades: 2012-09-11
Dela:

På Göteborgs universitet använder vi kakor (cookies) för att webbplatsen ska fungera på ett bra sätt för dig. Genom att surfa vidare godkänner du att vi använder kakor.  Vad är kakor?