From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
| Line 1: |
Line 1: |
| - | [[Image:1yf6.gif|left|200px]] | + | {{Seed}} |
| | + | [[Image:1yf6.png|left|200px]] |
| | | | |
| | <!-- | | <!-- |
| Line 9: |
Line 10: |
| | {{STRUCTURE_1yf6| PDB=1yf6 | SCENE= }} | | {{STRUCTURE_1yf6| PDB=1yf6 | SCENE= }} |
| | | | |
| - | '''Structure of a quintuple mutant of photosynthetic reaction center from rhodobacter sphaeroides'''
| + | ===Structure of a quintuple mutant of photosynthetic reaction center from rhodobacter sphaeroides=== |
| | | | |
| | | | |
| - | ==Overview==
| + | <!-- |
| - | The photosynthetic reaction center (RC) from purple bacteria converts light into chemical energy. Although the RC shows two nearly structurally symmetric branches, A and B, light-induced electron transfer in the native RC occurs almost exclusively along the A-branch to a primary quinone electron acceptor Q(A). Subsequent electron and proton transfer to a mobile quinone molecule Q(B) converts it to a quinol, Q(B)H(2). We report the construction and characterization of a series of mutants in Rhodobacter sphaeroides designed to reduce Q(B) via the B-branch. The quantum efficiency to Q(B) via the B-branch Phi(B) ranged from 0.4% in an RC containing the single mutation Ala-M260 --> Trp to 5% in a quintuple mutant which includes in addition three mutations to inhibit transfer along the A-branch (Gly-M203 --> Asp, Tyr-M210 --> Phe, Leu-M214 --> His) and one to promote transfer along the B-branch (Phe-L181 --> Tyr). Comparing the value of 0.4% for Phi(B) obtained in the AW(M260) mutant, which lacks Q(A), to the 100% quantum efficiency for Phi(A) along the A-branch in the native RC, we obtain a ratio for A-branch to B-branch electron transfer of 250:1. We determined the structure of the most effective (quintuple) mutant RC at 2.25 A (R-factor = 19.6%). The Q(A) site did not contain a quinone but was occupied by the side chain of Trp-M260 and a Cl(-). In this structure a nonfunctional quinone was found to occupy a new site near M258 and M268. The implications of this work to trap intermediate states are discussed. | + | The line below this paragraph, {{ABSTRACT_PUBMED_15865437}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 15865437 is the PubMed ID number. |
| | + | --> |
| | + | {{ABSTRACT_PUBMED_15865437}} |
| | | | |
| | ==About this Structure== | | ==About this Structure== |
| Line 32: |
Line 36: |
| | [[Category: Quinone movement]] | | [[Category: Quinone movement]] |
| | [[Category: Rhodobacter sphaeroide]] | | [[Category: Rhodobacter sphaeroide]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 16:14:44 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 12:40:16 2008'' |
Revision as of 09:40, 28 July 2008
Template:STRUCTURE 1yf6
Structure of a quintuple mutant of photosynthetic reaction center from rhodobacter sphaeroides
Template:ABSTRACT PUBMED 15865437
About this Structure
1YF6 is a Protein complex structure of sequences from Rhodobacter sphaeroides. Full crystallographic information is available from OCA.
Reference
Quinone (QB) reduction by B-branch electron transfer in mutant bacterial reaction centers from Rhodobacter sphaeroides: quantum efficiency and X-ray structure., Paddock ML, Chang C, Xu Q, Abresch EC, Axelrod HL, Feher G, Okamura MY, Biochemistry. 2005 May 10;44(18):6920-8. PMID:15865437
Page seeded by OCA on Mon Jul 28 12:40:16 2008
