New functional and biophysical insights into the mitochondrial Rieske iron-sulfur protein from genetic suppressor analysis in C. elegans.

ABSTRACT: Several intragenic mutations suppress the C. elegans isp-1(qm150) allele of the mitochondrial Rieske iron-sulfur protein (ISP), a catalytic subunit of Complex III of the respiratory chain. These mutations were located in a helical region of the "tether" span of ISP-1, distant from the primary mutation in the extrinsic head, and suppressed all pleiotropic phenotypes associated with the qm150 allele. Analysis of these suppressors revealed control of electron transfer into Complex III through a "spring-loaded" mechanism involving a binding force for formation of enzyme-substrate complex, counter balanced by forces (a chemical "spring") favoring helix formation in the tether. The primary P→S mutation results in inhibition of electron flow into the Q-cycle by decreasing the binding force, and t

SUBMITTER: Jafari G 

PROVIDER: S-EPMC4911972 | biostudies-literature | 2016 Apr-Jun

REPOSITORIES: biostudies-literature