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The promoter architectural landscape of the Salmonella PhoP regulon
Author(s) -
Zwir Igor,
Latifi Tammy,
Perez J. Christian,
Huang Henry,
Groisman Eduardo A.
Publication year - 2012
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2012.08036.x
Subject(s) - promoter , regulon , biology , gene , salmonella enterica , genetics , transcription (linguistics) , activator (genetics) , transcription factor , operon , binding site , virulence , gene expression , bacterial transcription , rna polymerase , rna , escherichia coli , linguistics , philosophy
Summary The DNA‐binding protein PhoP controls virulence and Mg 2+ homeostasis in the Gram‐negative pathogen Salmonella enterica serovar Typhimurium. PhoP regulates expression of a large number of genes that differ both in their ancestry and in the biochemical functions and physiological roles of the encoded products. This suggests that PhoP‐regulated genes are differentially expressed. To understand how a bacterial activator might generate varied gene expression behaviour, we investigated the cis‐ acting promoter features (i.e. the number of PhoP binding sites, as well as their orientation and location with respect to the sites bound by RNA polymerase and the sequences that constitute the PhoP binding sites) in 23 PhoP‐activated promoters. Our results show that natural PhoP‐activated promoters utilize only a limited number of combinations of cis ‐acting features – or promoter architectures. We determine that PhoP activates transcription by different mechanisms, and that ancestral and horizontally acquired PhoP‐activated genes have distinct promoter architectures.