3LBW

High resolution crystal structure of transmembrane domain of M2

3LBW の概要

• エントリーDOI: 10.2210/pdb3lbw/pdb
• 分子名称: M2 protein, 4-bromobenzoic acid, DI(HYDROXYETHYL)ETHER, ... (5 entities in total)
• 機能のキーワード: proton channel, m2tm, influenza a virus m2 protein, host cell membrane, hydrogen ion transport, ionic channel, transmembrane, virion, transport protein
• 由来する生物種: influenza A virus
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 11086.91

構造登録者

Acharya, R.,Polishchuk, A.L.,DeGrado, W.F. (登録日: 2010-01-08, 公開日: 2010-07-28, 最終更新日: 2023-09-06)

主引用文献

Acharya, R.,Carnevale, V.,Fiorin, G.,Levine, B.G.,Polishchuk, A.L.,Balannik, V.,Samish, I.,Lamb, R.A.,Pinto, L.H.,DeGrado, W.F.,Klein, M.L.
Structure and mechanism of proton transport through the transmembrane tetrameric M2 protein bundle of the influenza A virus.
Proc.Natl.Acad.Sci.USA, 107:15075-15080, 2010

PubMed Abstract: The M2 proton channel from influenza A virus is an essential protein that mediates transport of protons across the viral envelope. This protein has a single transmembrane helix, which tetramerizes into the active channel. At the heart of the conduction mechanism is the exchange of protons between the His37 imidazole moieties of M2 and waters confined to the M2 bundle interior. Protons are conducted as the total charge of the four His37 side chains passes through 2(+) and 3(+) with a pK(a) near 6. A 1.65 A resolution X-ray structure of the transmembrane protein (residues 25-46), crystallized at pH 6.5, reveals a pore that is lined by alternating layers of sidechains and well-ordered water clusters, which offer a pathway for proton conduction. The His37 residues form a box-like structure, bounded on either side by water clusters with well-ordered oxygen atoms at close distance. The conformation of the protein, which is intermediate between structures previously solved at higher and lower pH, suggests a mechanism by which conformational changes might facilitate asymmetric diffusion through the channel in the presence of a proton gradient. Moreover, protons diffusing through the channel need not be localized to a single His37 imidazole, but instead may be delocalized over the entire His-box and associated water clusters. Thus, the new crystal structure provides a possible unification of the discrete site versus continuum conduction models.

PubMed: 20689043
DOI: 10.1073/pnas.1007071107

実験手法

X-RAY DIFFRACTION (1.65 Å)