2C32

Co-axial association of recombinant eye lens aquaporin-0 observed in loosely packed 3D-crystals

2C32 の概要

• エントリーDOI: 10.2210/pdb2c32/pdb
• 関連するPDBエントリー: 1YMG
• 分子名称: LENS FIBER MAJOR INTRINSIC PROTEIN (1 entity in total)
• 機能のキーワード: eye lens, membrane protein, mixed micelle, gap junction, phosphorylation, transmembrane
• 由来する生物種: BOS TAURUS (BOVINE)
• 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: 28244.87

構造登録者

Palanivelu, D.V.,Schirmer, T. (登録日: 2005-10-03, 公開日: 2005-12-07, 最終更新日: 2023-12-13)

主引用文献

Palanivelu, D.V.,Kozono, D.E.,Engel, A.,Suda, K.,Lustig, A.,Agre, P.,Schirmer, T.
Co-Axial Association of Recombinant Eye Lens Aquaporin-0 Observed in Loosely Packed 3D-Crystals
J.Mol.Biol., 355:605-, 2006

PubMed Abstract: Aquaporin-0 (AQP0) is the major membrane protein in vertebrate eye lenses. It has been proposed that AQP0 tetramers mediate contact between membranes of adjacent lens fiber cells, which would be consistent with the extraordinarily narrow inter-cellular spacing. We have obtained 3D crystals of recombinant bovine AQP0 that diffract to 7.0 A resolution. The crystal packing was determined by molecular replacement and shows that, within the cubic lattice, AQP0 tetramers are associated head-to-head along their 4-fold axes. Oligomeric states larger than the tetramer were also observed in solution by native gel electrophoresis and analytical ultracentrifugation methods. In the crystals, there are no direct contacts between octamers, and it can thus be inferred that crystalline order is mediated solely by the detergent belts surrounding the membrane protein. Across the tetramer-tetramer interface, extracellular loops A and C interdigitate at the center and the perimeter of the octamer, respectively. The octamer structure is compared with that of the recently determined structure of truncated ovine AQP0 derived from electron diffraction of 2D crystals. Intriguingly, also in these crystals, octamers are observed, but with significantly different relative tetramer-tetramer orientations. The interactions observed in the loosely packed 3D crystals reported here may in fact represent an in vivo association mode between AQP0 tetramers from juxtaposed membranes in the eye lens.

PubMed: 16309700
DOI: 10.1016/J.JMB.2005.10.032

実験手法

X-RAY DIFFRACTION (7.01 Å)