Tandem gene amplification restores photosystem II accumulation in cytochrome b₅₅₉ mutants of cyanobacteria.

ABSTRACT: Cytochrome (Cyt) b₅₅₉ is a key component of the photosystem II complex (PSII) that is essential for its proper functioning and assembly. Site-directed mutants of the model cyanobacterium Synechocystis sp. PCC6803 with mutated heme axial ligands of Cyt b₅₅₉ have little PSII and are therefore unable to grow photoautotrophically. Here we describe two types of Synechocystis autotrophic transformants that retained the same mutations in Cyt b₅₅₉ but are able to accumulate PSII and grow photoautotrophically. Whole-genome sequencing revealed that all of these autotrophic transformants carried a variable number of tandem repeats (from 5 to 15) of chromosomal segments containing the psbEFLJ operon. RNA-seq analysis showed greatly increased transcript levels of the ps

SUBMITTER: Chiu YF 

PROVIDER: S-EPMC9297868 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature