SEN1990 is a predicted winged helix-turn-helix protein involved in the pathogenicity of Salmonella enterica serovar Enteritidis and the expression of the gene oafB in the SPI-17
Excisable genomic islands (EGIs) are horizontally acquired genetic elements that harbor an array of genes with diverse functions. ROD21 is an EGI found integrated in the chromosome of Salmonella enterica serovar Enteritidis ( Salmonella ser. Enteritidis). While this island is known to be involved in...
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Published in: | Frontiers in microbiology Vol. 14; p. 1236458 |
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Main Authors: | , , , , , , , , , , , , , , , |
Format: | Journal Article |
Language: | English |
Published: |
Frontiers Media S.A
03-11-2023
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Subjects: | |
Online Access: | Get full text |
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Summary: | Excisable genomic islands (EGIs) are horizontally acquired genetic elements that harbor an array of genes with diverse functions. ROD21 is an EGI found integrated in the chromosome of
Salmonella enterica
serovar Enteritidis (
Salmonella
ser. Enteritidis). While this island is known to be involved in the capacity of
Salmonella
ser. Enteritidis to cross the epithelial barrier and colonize sterile organs, the role of most ROD21 genes remains unknown, and thus, the identification of their function is fundamental to understanding the impact of this EGI on bacterium pathogenicity. Therefore, in this study, we used a bioinformatical approach to evaluate the function of ROD21-encoded genes and delve into the characterization of
SEN1990
, a gene encoding a putative DNA-binding protein. We characterized the predicted structure of SEN1990, finding that this protein contains a three-stranded winged helix-turn-helix (wHTH) DNA-binding domain. Additionally, we identified homologs of SEN1990 among other members of the EARL EGIs. Furthermore, we deleted
SEN1990
in
Salmonella
ser. Enteritidis, finding no differences in the replication or maintenance of the excised ROD21, contrary to what the previous Refseq annotation of the protein suggests. High-throughput RNA sequencing was carried out to evaluate the effect of the absence of
SEN1990
on the bacterium’s global transcription. We found a downregulated expression of
oafB
, an SPI-17-encoded acetyltransferase involved in O-antigen modification, which was restored when the deletion mutant was complemented ectopically. Additionally, we found that strains lacking
SEN1990
had a reduced capacity to colonize sterile organs in mice. Our findings suggest that
SEN1990
encodes a wHTH domain-containing protein that modulates the transcription of
oafB
from the SPI-17, implying a crosstalk between these pathogenicity islands and a possible new role of ROD21 in the pathogenesis of
Salmonella
ser. Enteritidis. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1664-302X 1664-302X |
DOI: | 10.3389/fmicb.2023.1236458 |