1trz

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spinqualitylabelsall models PDB ID 1trz Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
, resolution 1.6Å
Ligands:	, and
Coordinates:	save as pdb, mmCIF, xml

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

Contents 1 Overview 2 Disease 3 About this Structure 4 Reference

Overview

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)

Disease

Known diseases associated with this structure: Diabetes mellitus, rare form OMIM:[176730], Hyperproinsulinemia, familial OMIM:[176730], MODY, one form OMIM:[176730]

About this Structure

1TRZ is a Protein complex structure of sequences from [1]. The following page contains interesting information on the relation of 1TRZ with [Insulin]. Full crystallographic information is available from OCA.

Reference

Crystallographic evidence for dual coordination around zinc in the T3R3 human insulin hexamer., Ciszak E, Smith GD, Biochemistry. 1994 Feb 15;33(6):1512-7. PMID:8312271

Page seeded by OCA on Thu Mar 20 14:22:29 2008