1YMG

The Channel Architecture of Aquaporin O at 2.2 Angstrom Resolution

「1TM8」から置き換えられました

1YMG の概要

• エントリーDOI: 10.2210/pdb1ymg/pdb
• 分子名称: Lens fiber major intrinsic protein, nonyl beta-D-glucopyranoside (3 entities in total)
• 機能のキーワード: aqp0, integral membrane protein, mip26, lens, cataract, water channel, membrane protein
• 由来する生物種: Bos taurus (cattle)
• 細胞内の位置: Cell membrane; Multi-pass membrane protein: P06624
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28857.66

構造登録者

Harries, W.E.C.,Akhavan, D.,Miercke, L.J.W.,Khademi, S.,Stroud, R.M. (登録日: 2005-01-20, 公開日: 2005-02-08, 最終更新日: 2023-08-23)

主引用文献

Harries, W.E.C.,Akhavan, D.,Miercke, L.J.W.,Khademi, S.,Stroud, R.M.
The Channel Architecture of Aquaporin 0 at a 2.2-A Resolution
Proc.Natl.Acad.Sci.USA, 101:14045-14050, 2004

PubMed Abstract: We determined the x-ray structure of bovine aquaporin 0 (AQP0) to a resolution of 2.2 A. The structure of this eukaryotic, integral membrane protein suggests that the selectivity of AQP0 for water transport is based on the identity and location of signature amino acid residues that are hallmarks of the water-selective arm of the AQP family of proteins. Furthermore, the channel lumen is narrowed only by two, quasi-2-fold related tyrosine side chains that might account for reduced water conductance relative to other AQPs. The channel is functionally open to the passage of water because there are eight discreet water molecules within the channel. Comparison of this structure with the recent electron-diffraction structure of the junctional form of sheep AQP0 at pH 6.0 that was interpreted as closed shows no global change in the structure of AQP0 and only small changes in side-chain positions. We observed no structural change to the channel or the molecule as a whole at pH 10, which could be interpreted as the postulated pH-gating mechanism of AQP0-mediated water transport at pH >6.5. Contrary to the electron-diffraction structure, the comparison shows no evidence of channel gating induced by association of the extracellular domains of AQP0 at pH 6.0. Our structure aids the analysis of the interaction of the extracellular domains and the possibility of a cell-cell adhesion role for AQP0. In addition, our structure illustrates the basis for formation of certain types of cataracts that are the result of mutations.

PubMed: 15377788
DOI: 10.1073/pnas.0405274101

実験手法

X-RAY DIFFRACTION (2.24 Å)