Linked Life Data

16339942

Source:http://linkedlifedata.com/resource/pubmed/id/16339942

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 12
pubmed:dateCreated
2005-12-12
pubmed:abstractText
In Salmonella enterica, PhoP is the response regulator of the PhoP/PhoQ two-component regulatory system that controls the expression of various virulence factors in response to external Mg2+. Previous studies have shown that phosphorylation of a PhoP variant with a C-terminal His tag (PhoP(His)) enhances dimerization and binding to target DNA. Here, the effect of phosphorylation on the oligomerization and DNA binding properties of both wild-type PhoP (PhoP) and PhoP(His) are compared. Gel filtration chromatography showed that PhoP exists as a mixture of monomer and dimer regardless of its phosphorylation state. In contrast, unphosphorylated PhoP(His) was mostly monomeric, whereas PhoP(His) approximately P existed as a mixture of monomer and dimer. By monitoring the tryptophan fluorescence of the proteins and the fluorescence of the probe 1-anilinonaphthalene-8-sulfonic acid bound to them, it was found that PhoP and PhoP(His) exhibited different spectral properties. The interaction between PhoP or PhoP(His) and the PhoP box of the mgtA promoter was monitored by surface plasmon resonance. Binding of PhoP to the PhoP box was barely influenced by phosphorylation. In contrast, phosphorylation of PhoP(His) clearly increased the interaction of PhoP(His) with target DNA. Altogether, these data show that a His tag at the C-terminus of PhoP affects its biochemical properties, most likely by affecting its conformation and/or its oligomerization state. More importantly, these results show that wild-type PhoP dimerization and interaction with target DNA are independent of phosphorylation, which is in contrast to the previously proposed model.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1350-0872
pubmed:author
pubmed:issnType
Print
pubmed:volume
151
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3979-87
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Dimerization and DNA binding of the Salmonella enterica PhoP response regulator are phosphorylation independent.
pubmed:affiliation
Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada H3A 2B4.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't