4HZ1

Crystal Structure of Pseudomonas aeruginosa azurin with iron(II) at the copper-binding site.

Summary for 4HZ1

• Entry DOI: 10.2210/pdb4hz1/pdb
• Descriptor: Azurin, ACETATE ION, FE (II) ION, ... (4 entities in total)
• Functional Keywords: copper binding site, reductase, arsenite, electron transport
• Biological source: Pseudomonas aeruginosa
• Cellular location: Periplasm: P00282
• Total number of polymer chains: 4
• Total formula weight: 56254.11

Authors

McLaughlin, M.P.,Retegan, M.,Bill, E.,Payne, T.M.,Shafaat, H.S.,Pea, S.,Sudhamsu, J.,Ensign, A.A.,Crane, B.R.,Neese, F.,Holland, P.L. (deposition date: 2012-11-14, release date: 2012-12-12, Last modification date: 2024-10-16)

Primary citation

McLaughlin, M.P.,Retegan, M.,Bill, E.,Payne, T.M.,Shafaat, H.S.,Pena, S.,Sudhamsu, J.,Ensign, A.A.,Crane, B.R.,Neese, F.,Holland, P.L.
Azurin as a Protein Scaffold for a Low-coordinate Nonheme Iron Site with a Small-molecule Binding Pocket.
J.Am.Chem.Soc., 134:19746-19757, 2012

PubMed Abstract: The apoprotein of Pseudomonas aeruginosa azurin binds iron(II) to give a 1:1 complex, which has been characterized by electronic absorption, Mössbauer, and NMR spectroscopies, as well as X-ray crystallography and quantum-chemical computations. Despite potential competition by water and other coordinating residues, iron(II) binds tightly to the low-coordinate site. The iron(II) complex does not react with chemical redox agents to undergo oxidation or reduction. Spectroscopically calibrated quantum-chemical computations show that the complex has high-spin iron(II) in a pseudotetrahedral coordination environment, which features interactions with side chains of two histidines and a cysteine as well as the C═O of Gly45. In the (5)A(1) ground state, the d(z(2)) orbital is doubly occupied. Mutation of Met121 to Ala leaves the metal site in a similar environment but creates a pocket for reversible binding of small anions to the iron(II) center. Specifically, azide forms a high-spin iron(II) complex and cyanide forms a low-spin iron(II) complex.

PubMed: 23167247
DOI: 10.1021/ja308346b

Experimental method

X-RAY DIFFRACTION (2.2 Å)