Avoiding premature oxidation during the binding of Cu(II) to a dithiolate site in BsSCO. A rapid freeze-quench EPR study. FEBS Lett 2011 Mar 23;585(6):861-4
Date
02/22/2011Pubmed ID
21333651Pubmed Central ID
PMC3109496DOI
10.1016/j.febslet.2011.02.014Scopus ID
2-s2.0-79952575573 (requires institutional sign-in at Scopus site) 12 CitationsAbstract
The Bacillus subtilis version of SCO1 (BsSCO) is required for assembly of Cu(A) in cytochrome c oxidase and may function in thiol-disulfide exchange and/or copper delivery. BsSCO binds Cu(II) with ligation by two cysteines, one histidine and one water. However, copper is a catalyst of cysteine oxidation and BsSCO must avoid this reaction to remain functional. Time resolved, rapid freeze-quench (RFQ) electron paramagnetic resonance of apo-BsSCO reacting with Cu(II) reveals an initial Cu(II) species with two equatorially coordinated nitrogen atoms, but no sulfur. We propose that BsSCO evolves from this initial sulfur free coordination of Cu(II) to the final dithiolate species via a change in conformation, and that the initial binding by nitrogen is a means for BsSCO to avoid premature thiol oxidation.
Author List
Bennett B, Hill BCAuthor
Brian Bennett D.Phil. Professor and Chair in the Physics department at Marquette UniversityMESH terms used to index this publication - Major topics in bold
Bacterial ProteinsBinding Sites
Copper
Electron Spin Resonance Spectroscopy
Freezing
Kinetics
Membrane Proteins
Nitrogen
Organometallic Compounds
Oxidation-Reduction
Protein Binding
Sulfhydryl Compounds
Sulfur
