1ETJ

AZURIN MUTANT WITH MET 121 REPLACED BY GLU

Summary for 1ETJ

• Entry DOI: 10.2210/pdb1etj/pdb
• Descriptor: AZURIN, COPPER (II) ION (3 entities in total)
• Functional Keywords: electron transport, copper, periplasmic
• Biological source: Pseudomonas aeruginosa
• Cellular location: Periplasm: P00282
• Total number of polymer chains: 4
• Total formula weight: 56093.05

Authors

Karlsson, B.G.,Tsai, L.-C.,Nar, H.,Sanders-Loehr, J.,Bonander, N.,Langer, V.,Sjolin, L. (deposition date: 1997-01-11, release date: 1997-04-21, Last modification date: 2024-10-30)

Primary citation

Karlsson, B.G.,Tsai, L.C.,Nar, H.,Sanders-Loehr, J.,Bonander, N.,Langer, V.,Sjolin, L.
X-ray structure determination and characterization of the Pseudomonas aeruginosa azurin mutant Met121Glu.
Biochemistry, 36:4089-4095, 1997

PubMed Abstract: 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.

PubMed: 9100002
DOI: 10.1021/bi962416o

Experimental method

X-RAY DIFFRACTION (2.3 Å)