Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
NCBI PubMed ID: 23659637Publication DOI: 10.1111/mmi.12257Journal NLM ID: 8712028Publisher: Blackwell Publishing
Correspondence: Gottesms
helix.nih.gov
Institutions: Laboratory of Molecular Biology, National Cancer Institute, Bethesda, MD, 20892, USA
The PhoQ/PhoP two-component system activates many genes for lipopolysaccharide (LPS) modification when cells are grown at low Mg(2+) concentrations. An additional target of PhoQ and PhoP is MgrR, an Hfq-dependent small RNA that negatively regulates expression of eptB, also encoding a protein that carries out LPS modification. Examination of LPS confirmed that MgrR effectively silences EptB; the phosphoethanolamine modification associated with EptB is found in ∆mgrR::kan but not mgrR(+) cells. Sigma E has been reported to positively regulate eptB, although the eptB promoter does not have the expected Sigma E recognition motifs. The effects of Sigma E and deletion of mgrR on levels of eptB mRNA were independent, and the same 5' end was found in both cases. In vitro transcription and the behaviour of transcriptional and translational fusions demonstrate that Sigma E acts directly at the level of transcription initiation for eptB, from the same start point as Sigma 70. The results suggest that when Sigma E is active, synthesis of eptB transcript outstrips MgrR-dependent degradation; presumably the modification of LPS is important under these conditions. Adding to the complexity of eptB regulation is a second sRNA, ArcZ, which also directly and negatively regulates eptB.
Lipopolysaccharide, Genes, modification
Structure type: oligomer
Location inside paper: p.53, fig.1
Compound class: LPS
Contained glycoepitopes: IEDB_120354,IEDB_123890,IEDB_130650,IEDB_130659,IEDB_141807,IEDB_151531,IEDB_176772,IEDB_534864
Methods: PCR, DNA techniques, ESI-MS, genetic methods
Comments, role: Deep-rough mutant O”waaCF of E. coli MG1655
NCBI Taxonomy refs (TaxIDs): 562
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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