1E7N

The N-terminal domain of beta-B2-crystallin resembles the putative ancestral homodimer

1E7N の概要

• エントリーDOI: 10.2210/pdb1e7n/pdb
• 分子名称: BETA-CRYSTALLIN B2 (2 entities in total)
• 機能のキーワード: structural protein, eye lens protein, domain interactions, 2-fold symmetry
• 由来する生物種: MUS MUSCULUS (HOUSE MOUSE)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 23822.25

構造登録者

Clout, N.J.,Basak, A.,Wieligmann, K.,Bateman, O.A.,Jaenicke, R.,Slingsby, C. (登録日: 2000-08-31, 公開日: 2000-10-05, 最終更新日: 2024-05-08)

主引用文献

Clout, N.J.,Basak, A.,Wieligmann, K.,Bateman, O.A.,Jaenicke, R.,Slingsby, C.
The N-Terminal Domain of Betab2-Crystallin Resembles the Putative Ancestral Homodimer.
J.Mol.Biol., 304:253-, 2000

PubMed Abstract: betagamma-crystallins from the eye lens are proteins consisting of two similar domains joined by a short linker. All three-dimensional structures of native proteins solved so far reveal similar pseudo-2-fold pairing of the domains reflecting their presumed ancient origin from a single-domain homodimer. However, studies of engineered single domains of members of the betagamma-crystallin superfamily have not revealed a prototype ancestral solution homodimer. Here we report the 2.35 A X-ray structure of the homodimer of the N-terminal domain of rat betaB2-crystallin (betaB2-N). The two identical domains pair in a symmetrical manner very similar to that observed in native betagamma-crystallins, where N and C-terminal domains (which share approximately 35% sequence identity) are related by a pseudo-2-fold axis. betaB2-N thus resembles the ancestral prototype of the betagamma-crystallin superfamily as it self-associates in solution to form a dimer with an essentially identical domain interface as that between the N and C domains in betagamma-crystallins, but without the benefit of a covalent linker. The structure provides further evidence for the role of two-domain pairing in stabilising the protomer fold. These results support the view that the betagamma-crystallin superfamily has evolved by a series of gene duplication and fusion events from a single-domain ancestor capable of forming homodimers.

PubMed: 11090271
DOI: 10.1006/JMBI.2000.4197

実験手法

X-RAY DIFFRACTION (2.35 Å)