1qkp
HIGH RESOLUTION X-RAY STRUCTURE OF AN EARLY INTERMEDIATE IN THE BACTERIORHODOPSIN PHOTOCYCLEHIGH RESOLUTION X-RAY STRUCTURE OF AN EARLY INTERMEDIATE IN THE BACTERIORHODOPSIN PHOTOCYCLE
Structural highlights
FunctionBACR_HALSA Light-driven proton pump. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBacteriorhodopsin is the simplest known photon-driven proton pump and as such provides a model for the study of a basic function in bioenergetics. Its seven transmembrane helices encompass a proton translocation pathway containing the chromophore, a retinal molecule covalently bound to lysine 216 through a protonated Schiff base, and a series of proton donors and acceptors. Photoisomerization of the all-trans retinal to the 13-cis configuration initiates the vectorial translocation of a proton from the Schiff base, the primary proton donor, to the extracellular side, followed by reprotonation of the Schiff base from the cytoplasm. Here we describe the high-resolution X-ray structure of an early intermediate in the photocycle of bacteriorhodopsin, which is formed directly after photoexcitation. A key water molecule is dislocated, allowing the primary proton acceptor, Asp 85, to move. Movement of the main-chain Lys 216 locally disrupts the hydrogen-bonding network of helix G, facilitating structural changes later in the photocycle. High-resolution X-ray structure of an early intermediate in the bacteriorhodopsin photocycle.,Edman K, Nollert P, Royant A, Belrhali H, Pebay-Peyroula E, Hajdu J, Neutze R, Landau EM Nature. 1999 Oct 21;401(6755):822-6. PMID:10548112[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
|
| ||||||||||||||||||