Label-free quantitative proteomic analysis of DNA methyltransferase mutants of the cyanobacterium Synechocystis sp. PCC 6803 – Analysis of total protein extracts

ABSTRACT: Total protein and membrane-enriched fractions of Synechocystis sp. PCC 6803 wild type (WT) and mutant strains affected with inactivated DNA methyltransferase genes were analyzed by LC-HDMSE. The mutation of the DNA methyltransferase gene sll0729 encoding M.Ssp6803II initially led to a strong phenotype, including a lowered chlorophyll/phycocyanin ratio, impaired growth, and alterations in gene expression. Prolonged cultivation revealed instability of the initially obtained phenotype. Colonies showing normal pigmentation and WT-like growth appeared regularly and in high frequencies on agar plates. These colonies represent suppressor mutants, since the sll0729 gene is still completely inactivated and methylation of the M.Ssp6803II target GGCC sites does not occur. The proteomic analysis comprises the WT, two strains of suppressor mutants sll0729_1 and sll0729_15 as well as mutants of the DNA methyltransferase genes slr6095 and sll8009. For each of these five strains we investigated three biological replicates. Comparisons between the WT and these two suppressor mutant strains, but also between them and the slr6095 and sll8009 mutants enabled the detection of expression differences, which are specifically linked to the absence of M.Ssp6803II-related DNA methylation.

OTHER RELATED OMICS DATASETS IN: GSE126283 GSE126282 GSE126285

INSTRUMENT(S): Synapt MS

ORGANISM(S): Synechocystis Sp. (strain Pcc 6803 / Kazusa)

SUBMITTER: Stefan Mikkat  

LAB HEAD: Martin Hagemann

PROVIDER: PXD012751 | Pride | 2019-06-26

REPOSITORIES: Pride