A protease-mediated mechanism regulates the cytochrome c₆/plastocyanin switch in Synechocystis sp. PCC 6803.

ABSTRACT: After the Great Oxidation Event (GOE), iron availability was greatly decreased, and photosynthetic organisms evolved several alternative proteins and mechanisms. One of these proteins, plastocyanin, is a type I blue-copper protein that can replace cytochrome c₆ as a soluble electron carrier between cytochrome b₆f and photosystem I. In most cyanobacteria, expression of these two alternative proteins is regulated by copper availability, but the regulatory system remains unknown. Herein, we provide evidence that the regulatory system is composed of a BlaI/CopY-family transcription factor (PetR) and a BlaR-membrane protease (PetP). PetR represses petE (plastocyanin) expression and activates petJ (cytochrome c₆), while P

SUBMITTER: Garcia-Canas R 

PROVIDER: S-EPMC7865156 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature