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Genes encoding putative DEAD‐box RNA helicases in Listeria monocytogenes EGD‐e are needed for growth and motility at 3°C
Author(s) -
Markkula Annukka,
Mattila Mirjami,
Lindström Miia,
Korkeala Hannu
Publication year - 2012
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2012.02761.x
Subject(s) - biology , listeria monocytogenes , motility , dead box , gene , mutant , microbiology and biotechnology , rna , helicase , pathogen , bacteria , genetics
Summary Quantitative RT‐PCR revealed that transcripts of all four putative DEAD‐box RNA helicase genes of the psychrotrophic pathogen Listeria monocytogenes EGD‐e are found at higher levels in organisms grown at 3°C than at 37°C. At 3°C, growth of the three corresponding gene deletion mutants Δ lmo0866 , Δ lmo1450 and Δ lmo1722 was clearly restricted. The minimum growth temperatures of the three mutants were also higher than that of the wild‐type EGD‐e. In addition to inability to grow at 3°C, growth of Δ lmo0866 and Δ lmo1722 was reduced at 25°C, suggesting special roles of Lmo0866 and Lmo1722 in growth at suboptimal temperatures. Growth of Δ lmo1450 was restricted not only at 3°C and 25°C, but also at 37°C, suggesting that Lmo1450 plays a universal role in growth of L. monocytogenes EGD‐e. Moreover, cold‐sensitive Δ lmo0866 , Δ lmo1450 and Δ lmo1722 were impaired in motility. The Δ lmo0866 and Δ lmo1450 strains were non‐motile, while Δ lmo1722 showed reduced motility. This study shows that the putative DEAD‐box RNA helicase genes lmo0866 , lmo1450 and lmo1722 are necessary for cold tolerance and motility of L. monocytogenes EGD‐e.