2uyd

File:2uyd.jpg

spinqualitylabelsall models 2uyd, resolution 2.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D

CRYSTAL STRUCTURE OF THE SMHASA MUTANT H83A

Overview

Heme carrier HasA has a unique type of histidine/tyrosine heme iron ligation in which the iron ion is in a thermally driven two spin state equilibrium. We recently suggested that the H-bonding between Y75 and the invariantly conserved residue H83 modulates the strength of the Fe-Y75 bond. To unravel the role of H83, we characterize the iron ligation and the electronic properties of both wild type and H83A mutant by a variety of spectroscopic techniques. While H83 in wild type modulates the strength of the Tyr-iron bond, its removal causes detachment of the tyrosine ligand, thus giving rise to a series of pH dependent equilibria among species with different axial ligation. The five coordinated species detected at physiological pH may represent a possible intermediate of the heme transfer mechanism to the receptor.

About this Structure

2UYD is a Single protein structure of sequence from Serratia marcescens with ZN, ACT and HEM as ligands. Known structural/functional Sites: AC1, AC2, AC3, AC4, AC5, AC7, AC8, AC9, BC1 and BC2. Full crystallographic information is available from OCA.

Reference

Deciphering the structural role of histidine 83 for heme binding in hemophore HasA., Caillet-Saguy C, Turano P, Piccioli M, Lukat-Rodgers GS, Czjzek M, Guigliarelli B, Izadi-Pruneyre N, Rodgers KR, Delepierre M, Lecroisey A, J Biol Chem. 2007 Dec 27;. PMID:18162469

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