4HHG: Crystal Structure Of The Pseudomonas Aeruginosa Azurin, Ruh107no Yoh109

We have designed ruthenium-modified Pseudomonas aeruginosa azurins that incorporate 3-nitrotyrosine (NO2YOH) between Ru(2,2'-bipyridine)2(imidazole)(histidine) and Cu redox centers in electron transfer (ET) pathways. We investigated the structures and reactivities of three different systems: RuH107NO2YOH109, RuH124NO2YOH122, and RuH126NO2YOH122. RuH107NO2YOH109, unlabeled H124NO2YOH122, and unlabeled H126NO2YOH122 were structurally characterized. The pKa's of NO2YOH at positions 122 and 109 are 7.2 and 6.0, respectively. Reduction potentials of 3-nitrotyrosinate (NO2YO(-))-modified azurins were estimated from cyclic and differential pulse voltammetry data: oxidation of NO2YO(-)122 occurs near 1.1 versus NHE; oxidation of NO2YO(-)109 is near 1.2 V. Our analysis of transient optical spectroscopic experiments indicates that hopping via NO2YO(-) enhances Cu(I) oxidation rates over single-step ET by factors of 32 (RuH107NO2YO(-)109), 46 (RuH126NO2YO(-)122), and 13 (RuH124NO2YO(-)122).
PDB ID: 4HHGDownload
MMDB ID: 105257
PDB Deposition Date: 2012/10/9
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 1.6  Å
Source Organism:
Similar Structures:
Biological Unit for 4HHG: monomeric; determined by author
Molecular Components in 4HHG
Label Count Molecule
Protein (1 molecule)
Azurin(Gene symbol: azu)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB