1TRZ

CRYSTALLOGRAPHIC EVIDENCE FOR DUAL COORDINATION AROUND ZINC IN THE T3R3 HUMAN INSULIN HEXAMER

1TRZ の概要

• エントリーDOI: 10.2210/pdb1trz/pdb
• 分子名称: INSULIN, ZINC ION, CHLORIDE ION, ... (6 entities in total)
• 機能のキーワード: hormone
• 由来する生物種: Homo sapiens (human); 詳細
• 細胞内の位置: Secreted: P01308 P01308
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 11860.02

構造登録者

Ciszak, E.,Smith, G.D. (登録日: 1993-11-19, 公開日: 1994-01-31, 最終更新日: 2024-11-06)

主引用文献

Ciszak, E.,Smith, G.D.
Crystallographic evidence for dual coordination around zinc in the T3R3 human insulin hexamer.
Biochemistry, 33:1512-1517, 1994

PubMed Abstract: The T3R3 human insulin hexamer (T and R referring to extended and alpha-helical conformations, respectively, of the first eight residues of the B-chain), complexed to two zinc ions, crystallizes in space group R3 with hexagonal cell constants a = 80.64 and c = 37.78 A. The structure has been refined to a residual of 0.172 using 9225 independent data to 1.6-A resolution. The asymmetric unit consists of a TR dimer, and the insulin hexamer is generated by the action of the crystallographic 3-fold axis. The conformation of one insulin trimer is nearly identical to that of the T6 hexamer, while the other trimer approximates that of the R6 hexamer, except for the three N-terminal B-chain residues that adopt an extended rather than an alpha-helical conformation. Each of the two zinc ions, which lie on the crystallographic 3-fold axis and exhibit two different, disordered coordination geometries, is coordinated by the imidazole groups of three symmetry-related B10 histidine residues. The coordination sphere of the zinc in the T3 trimer is either tetrahedral, with the fourth site filled by a chloride ion, or octahedral, completed by three water molecules. The coordination of the zinc in the 12-A narrow channel in the R3 trimer is tetrahedral, with either a second chloride ion or a water molecule completing the coordination sphere. The putative off-axial zinc binding sites that result from the T-->R transition of monomer II do not contain zinc ion, but instead are filled with clusters of ordered water molecules.(ABSTRACT TRUNCATED AT 250 WORDS)

PubMed: 8312271
DOI: 10.1021/bi00172a030

実験手法

X-RAY DIFFRACTION (1.6 Å)