RNA metabolism is important as RNA acts as a link between genomic information and functional biomolecules, thereby playing a critical role in cellular response to environment. We investigated the role of DEAD-box RNA helicases in low-temperature adapted growth of P. syringae, as this group of enzymes play an essential role in modulation of RNA secondary structures. This is the first report on the assessment of all major DEAD-box RNA helicases in any Antarctic bacterium. Of the five RNA helicases, three (srmB, csdA, and dbpA) are important for the growth of the Antarctic P. syringae at low temperature. However, the requisite role of dbpA and the indispensable requirement of csdA for low-temperature adapted growth are a novel finding of this study. Growth analysis of combinatorial deletion strains was performed to understand the functional interaction among helicase genes. Similarly, genetic complementation of RNA helicase mutants was conducted for identification of gene redundancy in P. syringae.
Keywords: RNA helicases; cold adaptation; functional complementation; gene disruption; growth analysis; homologous recombination.