The Importance of the C-Terminal Cys Pair of Phosphoribulokinase in Phototrophs in Thioredoxin-Dependent Regulation.

ABSTRACT: Phosphoribulokinase (PRK), one of the enzymes in the Calvin-Benson cycle, is a well-known target of thioredoxin (Trx), which regulates various enzyme activities by the reduction of disulfide bonds in a light-dependent manner. PRK has two Cys pairs conserved in the N-terminal and C-terminal regions, and the N-terminal one near the active site is thought to be responsible for the regulation. The flexible clamp loop located between the N-terminal two Cys residues has been deemed significant to Trx-mediated regulation. However, cyanobacterial PRK is also subject to Trx-dependent activation despite the lack of this clamp loop. We, therefore, compared Trx-mediated regulation of PRK from the cyanobacterium Anabaena sp. PCC 7120 (A.7120_PRK) and that from the land plant Arabidopsis thaliana (AtPRK

SUBMITTER: Fukui K 

PROVIDER: S-EPMC9199185 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature