Disruption of a spe-like open reading frame alters polyamine content and psbA-2 mRNA stability in the cyanobacterium Synechocystis sp. PCC 6803

Abstract

In Synechocystis 6803, transcripts of the psbA-2 gene encoding the reaction-center protein D1 of photosystem II are short-lived in light but stable in darkness. No dark-stabilization was observed if the genomic region downstream from the psbA-2 gene was disrupted. The deleted fragment was found to include an open reading frame (ORF) with striking similarity to the spe gene encoding arginine decarboxylase (L-arginine carboxy-lyase, EC 4.1.1.19), which is involved in the biosynthesis of polyamines. The spermidine content of the mutants with a disrupted ORF was observed to be lower than in the wild-type suggesting that polyamines may play a role in the stability of the psbA-2 mRNA.