Role of DEAD-box RNA helicases in low-temperature adapted growth of Antarctic Pseudomonas syringae Lz4W

Pseudomonas syringae possesses genes for all five major DEAD-box RNA helicases, rhlE, srmB, csdA, dbpA, and rhlB, that are found in gamma-proteobacteria. Bioinfor matic analysis of the RNA helicase genes provided detailed insights into their genomic organization, promoter characteristics, regulatory 3 ' regions, and sequence similarity. Disruption of rhlB and rhlE genes did not have any effect on growth of the P. syringae mutants at optimum (22 degrees C) or at low (4 degrees C) temperatures. On the other hand, disrup tion of srmB and dbpA genes caused a slow-growing phenotype in the mutants at low temperature (4 degrees C). In comparison to the above-mentioned helicases, deletion of csdA gene caused the mutant (Delta csdA) to be totally incapable of growing at 4 degrees C while marginally affecting the growth (resulting in slow growth) at the optimum temperature (22 degrees C). Functional complementation studies revealed that RNA helicases are functionally non-redundant, as the roles performed by different helicases are individual and specific.

Automated summary

Pseudomonas syringae possesses genes for all five major DEAD-box RNA helicases, and disruption of different helicase genes leads to varying effects on the growth of P. syringae mutants at different temperatures. Functional complementation studies show that different helicases have individual and specific roles.