1K6N

E(L212)A,D(L213)A Double Mutant Structure of Photosynthetic Reaction Center from Rhodobacter Sphaeroides

1K6N の概要

• エントリーDOI: 10.2210/pdb1k6n/pdb
• 関連するPDBエントリー: 1k6l 1pcr 1qov
• 分子名称: PHOTOSYNTHETIC REACTION CENTER L SUBUNIT, CARDIOLIPIN, PHOTOSYNTHETIC REACTION CENTER M SUBUNIT, ... (11 entities in total)
• 機能のキーワード: double mutant photosynthetic reaction center, proton transfer, membrane protein, photosynthesis
• 由来する生物種: Rhodobacter sphaeroides; 詳細
• 細胞内の位置: Cellular chromatophore membrane; Multi-pass membrane protein: P02954 P02953; Cellular chromatophore membrane; Single-pass membrane protein: P11846
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 104859.85

構造登録者

Pokkuluri, P.R.,Laible, P.D.,Deng, Y.-L.,Wong, T.N.,Hanson, D.K.,Schiffer, M. (登録日: 2001-10-16, 公開日: 2002-08-07, 最終更新日: 2023-08-16)

主引用文献

Pokkuluri, P.R.,Laible, P.D.,Deng, Y.L.,Wong, T.N.,Hanson, D.K.,Schiffer, M.
The structure of a mutant photosynthetic reaction center shows unexpected changes in main chain orientations and quinone position.
Biochemistry, 41:5998-6007, 2002

PubMed Abstract: We report on the unexpected structural changes caused by substitution of acidic amino acids in the Q(B) binding pocket of the bacterial photosynthetic reaction center by alanines. The mutations targeted key residues L212Glu and L213Asp of this transmembrane protein-cofactor complex. The amino acid substitutions in the L212Ala-L213Ala mutant reaction center ("AA") were known to affect the delivery of protons after the light-induced generation of Q(B)(-), which renders the AA strain incapable of photosynthetic growth. The AA structure not only revealed side chain rearrangements but also showed movement of the main chain segments that are contiguous with the mutation sites. The alanine substitutions caused an expansion of the cavity rather than its collapse. In addition, Q(B) is found mainly in the binding site that is proximal to the iron-ligand complex (closest to Q(A)) as opposed to its distal binding site (furthest from Q(A)) in the structure of the wild-type reaction center. The observed rearrangements in the structure of the AA reaction center establish a new balance between charged residues of an interactive network near Q(B). This structurally and electrostatically altered complex forms the basis for future understanding of the structural basis for proton transfer in active reaction centers which retain the alanine substitutions but carry a distant compensatory mutation.

PubMed: 11993994
DOI: 10.1021/bi0118963

実験手法

X-RAY DIFFRACTION (3.1 Å)