1etj
From Proteopedia
AZURIN MUTANT WITH MET 121 REPLACED BY GLU
Overview
The Met121Glu azurin mutant has been crystallized and the structure determined at a resolution of 2.3 A. In the crystal structure a carboxyl oxygen of Met121Glu is coordinated to the metal at a distance of 2.2 A. Single-crystal resonance Raman spectroscopy was used to show that the glutamic acid residue in the copper site was in the protonated state. Titration of this residue gives rise to a number of unusual, pH-dependent properties: as the pH is increased from 4 to 8, the S(Cys)-Cu ligand-to-metal charge transfer bands are blue shifted and their intensity ratio is reversed, the EPR signal changes from type 1 copper to a new form of protein-bound copper, and the redox potential changes from 370 to 180 mV. The spectroscopic changes in this pH interval are consistent with a two-state model. From the pH dependence of the optical and EPR spectra, pKa = 5.0 for the glutamic acid in the oxidized protein was determined.
About this Structure
1ETJ is a Single protein structure of sequence from Pseudomonas aeruginosa. Full crystallographic information is available from OCA.
Reference
X-ray structure determination and characterization of the Pseudomonas aeruginosa azurin mutant Met121Glu., Karlsson BG, Tsai LC, Nar H, Sanders-Loehr J, Bonander N, Langer V, Sjolin L, Biochemistry. 1997 Apr 8;36(14):4089-95. PMID:9100002 Page seeded by OCA on Fri May 2 15:30:09 2008
