H135A controls the redox activity of the Sco copper center. Kinetic and spectroscopic studies of the His135Ala variant of Bacillus subtilis Sco.

ABSTRACT: Sco-like proteins contain copper bound by two cysteines and a histidine residue. Although their function is still incompletely understood, there is a clear involvement with the assembly of cytochrome oxidases that contain the Cu(A) center in subunit 2, possibly mediating the transfer of copper into the Cu(A) binuclear site. We are investigating the reaction chemistry of BSco, the homologue from Bacillus subtilis. Our studies have revealed that BSco behaves more like a redox protein than a metallochaperone. The essential H135 residue that coordinates copper plays a role in stabilizing the Cu(II) rather than the Cu(I) form. When H135 is mutated to alanine, the oxidation rate of both hydrogen peroxide and one-electron outer-sphere reductants increases by 3 orders of magnitude, suggestive of a

SUBMITTER: Siluvai GS 

PROVIDER: S-EPMC2821211 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature