4HHG

Crystal structure of the Pseudomonas aeruginosa azurin, RuH107NO YOH109

Summary for 4HHG

• Entry DOI: 10.2210/pdb4hhg/pdb
• Descriptor: Azurin, COPPER (II) ION, DELTA-BIS(2,2'-BIPYRIDINE)IMIDAZOLE RUTHENIUM (II), ... (4 entities in total)
• Functional Keywords: greek key, electron transfer, nitrosylated, electron transport
• Biological source: Pseudomonas aeruginosa
• Cellular location: Periplasm: P00282
• Total number of polymer chains: 1
• Total formula weight: 14593.87

Authors

Herrera, N.,Warren, J.J.,Gray, H.B. (deposition date: 2012-10-09, release date: 2012-11-21, Last modification date: 2025-03-26)

Primary citation

Warren, J.J.,Herrera, N.,Hill, M.G.,Winkler, J.R.,Gray, H.B.
Electron Flow through Nitrotyrosinate in Pseudomonas aeruginosa Azurin.
J.Am.Chem.Soc., 135:11151-11158, 2013

PubMed Abstract: 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).

PubMed: 23859602
DOI: 10.1021/ja403734n

Experimental method

X-RAY DIFFRACTION (1.6 Å)