English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Summary    Cytochrome (Cyt)  b  559  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  b  559  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  b  559  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  psbEFLJ  operon in these autotrophic transformants. Multiple copies of the  psbEFLJ  operon in these transformants were only maintained during autotrophic growth, while its copy numbers gradually decreased under photoheterotrophic conditions. Two‐dimensional PAGE analysis of membrane proteins revealed a strong deficiency in PSII complexes in the Cyt  b  559  mutants that was reversed in the autotrophic transformants.  These results illustrate how tandem gene amplification restores PSII accumulation and photoautotrophic growth in Cyt  b  559  mutants of cyanobacteria, and may serve as an important adaptive mechanism for cyanobacterial survival.

Tandem gene amplification restores photosystem II accumulation in cytochrome b 559 mutants of cyanobacteria