Avoiding Premature Oxidation During the Binding of Cu(II) to a Dithiolate Site in BsSCO. A Rapid Freeze-Quench EPR Study

Authors

Brian Bennett, Marquette UniversityFollow
Bruce C. Hill, Queen's University - Kingston, Ontario

Document Type

Article

Language

eng

Format of Original

4 p.

Publication Date

3-23-2011

Publisher

FEBS

Source Publication

FEBS Letters

Source ISSN

0014-5793

Original Item ID

doi: 10.1016/j.febslet.2011.02.014

Abstract

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.

Comments

Accepted version. FEBS Letters, Vol. 585, No. 6 (March 23, 2011): 861-864. DOI. © 2011 Federation of European Biochemical Societies. Used with permission.

Brian Bennett was affiliated with the Medical College of Wisconsin at the time of publication.

Recommended Citation

Bennett, Brian and Hill, Bruce C., "Avoiding Premature Oxidation During the Binding of Cu(II) to a Dithiolate Site in BsSCO. A Rapid Freeze-Quench EPR Study" (2011). Physics Faculty Research and Publications. 51.
https://epublications.marquette.edu/physics_fac/51