Putative transcription antiterminator RfaH contributes to Erwinia amylovora virulence.

Autor: Klee SM; Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, Pennsylvania, USA.; Department of Microbiology, University of Washington, Seattle, Washington, USA., Sinn JP; Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, Pennsylvania, USA., Held J; Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, Pennsylvania, USA.; The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA., Vosburg C; Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, Pennsylvania, USA., Holmes AC; Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, Pennsylvania, USA.; Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA.; Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA., Lehman BL; The Pennsylvania State University Fruit Research and Extension Center, Biglerville, Pennsylvania, USA., Peter KA; Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, Pennsylvania, USA.; The Pennsylvania State University Fruit Research and Extension Center, Biglerville, Pennsylvania, USA., McNellis TW; Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, Pennsylvania, USA.
Jazyk: angličtina
Zdroj: Molecular plant pathology [Mol Plant Pathol] 2022 Nov; Vol. 23 (11), pp. 1686-1694. Date of Electronic Publication: 2022 Aug 05.
DOI: 10.1111/mpp.13254
Abstrakt: The gram-negative bacterium Erwinia amylovora causes fire blight disease of apple and pear trees. The exopolysaccharide amylovoran and lipopolysaccharides are essential E. amylovora virulence factors. Production of amylovoran and lipopolysaccharide is specified in part by genes that are members of long operons. Here, we show that full virulence of E. amylovora in apple fruitlets and tree shoots depends on the predicted transcription antiterminator RfaH. RfaH reduces pausing in the production of long transcripts having an operon polarity suppressor regulatory element within their promoter region. In E. amylovora, only the amylovoran operon and a lipopolysaccharide operon have such regulatory elements within their promoter regions and in the correct orientation. These operons showed dramatically increased polarity in the ΔrfaH mutant compared to the wild type as determined by RNA sequencing. Amylovoran and lipopolysaccharide production in vitro was reduced in rfaH mutants compared to the wild type, which probably contributes to the rfaH mutant virulence phenotype. Furthermore, type VI secretion cluster 1, which contributes to E. amylovora virulence, showed reduced expression in ΔrfaH compared to the wild type, although without an increase in polarity. The data suggest that E. amylovora RfaH directly, specifically, and exclusively suppresses operon polarity in the amylovoran operon and a lipopolysaccharide operon.
(© 2022 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)
Databáze: MEDLINE
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