Cooperation of group 2 σ factors, SigD and SigE for light‐induced transcription in the cyanobacterium Synechocystis sp. PCC 6803

Abstract

A light‐inducible σ factor of RNA polymerase, SigD, can contributes to the light‐induced transcription of psbA in the cyanobacterium Synechocystis sp. PCC 6803. Here, another light‐induced σ factor, SigE, was characterized together with SigD. Results indicated that SigE also contributes to light‐induced transcription on the cpcBACD, psbA, petBD and psaAB promoters whose potential sequences are of the Escherichia coli σ⁷⁰‐type. SigD and SigE interfere with each other's expression. A rhythmic expression, in which the periodic peak of SigE exhibits a 24‐h interval according to the upcoming night, was observed at the protein level. The cooperation of group 2 σ factors, SigD and SigE, for light‐induced transcription was discussed.