1ry5
From Proteopedia
PHOTOSYNTHETIC REACTION CENTER MUTANT FROM RHODOBACTER SPHAEROIDES WITH ASP L213 REPLACED WITH ASN
Structural highlights
FunctionRCEL_CERSP The reaction center is a membrane-bound complex that mediates the initial photochemical event in the electron transfer process of photosynthesis. 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 PubMedIn the photosynthetic reaction center (RC) from Rhodobacter sphaeroides, the reduction of a bound quinone molecule Q(B) is coupled with proton uptake. When Asp-L213 is replaced by Asn, proton transfer is inhibited. Proton transfer was restored by two second-site revertant mutations, Arg-M233-->Cys and Arg-H177-->His. Kinetic effects of Cd(2+) on proton transfer showed that the entry point in revertant RCs to be the same as in the native RC. The structures of the parental and two revertant RCs were determined at resolutions of 2.10, 1.80, and 2.75 A. From the structures, we were able to delineate alternate proton transfer pathways in the revertants. The main changes occur near Glu-H173, which allow it to substitute for the missing Asp-L213. The electrostatic changes near Glu-H173 cause it to be a good proton donor and acceptor, and the structural changes create a cavity which accommodates water molecules that connect Glu-H173 to other proton transfer components. X-Ray structure determination of three mutants of the bacterial photosynthetic reaction centers from Rb. sphaeroides; altered proton transfer pathways.,Xu Q, Axelrod HL, Abresch EC, Paddock ML, Okamura MY, Feher G Structure. 2004 Apr;12(4):703-15. PMID:15062092[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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