a small rna controls expression of the chitinase chia in listeria monocytogenes一个小rna控制的表达几丁质酶chia在单核细胞增多性李斯特氏菌.pdfVIP

A Small RNA Controls Expression of the Chitinase ChiA in Listeria monocytogenes 1 2 1 3 Jesper S. Nielsen , Marianne Halberg Larsen , Eva Maria Sternkopf Lillebæk , Teresa M. Bergholz , 1 3 3 1 Mie H. G. Christiansen , Kathryn J. Boor , Martin Wiedmann , Birgitte H. Kallipolitis * 1 Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark, 2 Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, Frederiksberg, Denmark, 3 Department of Food Science, Cornell University, Ithaca, New York, United States of America Abstract In recent years, more than 60 small RNAs (sRNAs) have been identified in the gram-positive human pathogen Listeria monocytogenes, but their putative roles and mechanisms of action remain largely unknown. The sRNA LhrA was recently shown to be a post-transcriptional regulator of a single gene, lmo0850, which encodes a small protein of unknown function. LhrA controls the translation and degradation of the lmo0850 mRNA by an antisense mechanism, and it depends on the RNA chaperone Hfq for efficient binding to its target. In the present study, we sought to gain more insight into the functional role of LhrA in L. monocytogenes. To this end, we determined the effects of LhrA on global-wide gene expression. We observed that nearly 300 genes in L. monocytogenes are either positively or negatively affected by LhrA. Among these genes, we identified lmo0302 and chiA as direct targets of LhrA, thus establishing LhrA as a multiple target regulator. Lmo0302 encodes a hypothetical protein