1NKZ

Crystal structure of LH2 B800-850 from Rps. acidophila at 2.0 Angstrom resolution

1NKZ の概要

• エントリーDOI: 10.2210/pdb1nkz/pdb
• 関連するPDBエントリー: 1KZU
• 分子名称: Light-harvesting protein B-800/850, alpha chain, Light-harvesting protein B-800/850, beta chain, Rhodopin b-D-glucoside, ... (7 entities in total)
• 機能のキーワード: light harvesting complex ii, trans-membrane helices, rhodopin glucoside, bacteriochlorophyll a, photosynthesis, membrane protein
• 由来する生物種: Rhodoblastus acidophilus; 詳細
• 細胞内の位置: Cell inner membrane; Single-pass type II membrane protein: P26789 P26790
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 45394.09

構造登録者

Papiz, M.Z.,Prince, S.M.,Howard, T.,Cogdell, R.J.,Isaacs, N.W. (登録日: 2003-01-06, 公開日: 2003-02-25, 最終更新日: 2024-03-13)

主引用文献

Papiz, M.Z.,Prince, S.M.,Howard, T.,Cogdell, R.J.,Isaacs, N.W.
The structure and thermal motion of the B800-850 LH2 complex from Rps. acidophila at 2.0 A resolution and 100K : new structural features and functionally relevant motions.
J.Mol.Biol., 326:1523-1538, 2003

PubMed Abstract: The structure at 100K of integral membrane light-harvesting complex II (LH2) from Rhodopseudomonas acidophila strain 10050 has been refined to 2.0A resolution. The electron density has been significantly improved, compared to the 2.5A resolution map, by high resolution data, cryo-cooling and translation, libration, screw (TLS) refinement. The electron density reveals a second carotenoid molecule, the last five C-terminal residues of the alpha-chain and a carboxy modified alpha-Met1 which forms the ligand of the B800 bacteriochlorophyll. TLS refinement has enabled the characterisation of displacements between molecules in the complex. B850 bacteriochlorophyll molecules are arranged in a ring of 18 pigments composed of nine approximate dimers. These pigments are strongly coupled and at their equilibrium positions the excited state dipole interaction energies, within and between dimers, are approximately 370cm(-1) and 280cm(-1), respectively. This difference in coupling energy is similar in magnitude to changes in interaction energies arising from the pigment displacements described by TLS tensors. The displacements appear to be non-random in nature and appear to be designed to optimise the modulation of pigment energy interactions. This is the first time that LH2 pigment displacements have been quantified experimentally. The calculated energy changes indicate that there may be significant contributions to inter-pigment energy interactions from molecular displacements and these may be of importance to photosynthetic energy transfer.

PubMed: 12595263
DOI: 10.1016/S0022-2836(03)00024-X

実験手法

X-RAY DIFFRACTION (2 Å)