Interaction of an IHF-like protein with the Rhizobium etli nifA promoter

Traki Benhassine; Maarten Fauvart; Jos Vanderleyden; Jan Michiels

doi:10.1111/j.1574-6968.2007.00699.x

Interaction of an IHF-like protein with the Rhizobium etli nifA promoter

FEMS Microbiol Lett. 2007 Jun;271(1):20-6. doi: 10.1111/j.1574-6968.2007.00699.x. Epub 2007 Apr 2.

Authors

Traki Benhassine¹, Maarten Fauvart, Jos Vanderleyden, Jan Michiels

Affiliation

¹ Laboratoire de Biologie Cellulaire et Moléculaire, Faculté des Sciences Biologiques, USTHB, Alger, Algérie.

PMID: 17403047
DOI: 10.1111/j.1574-6968.2007.00699.x

Abstract

The nifA gene fulfills an essential role in the regulation of nitrogen fixation genes in Rhizobium etli. Transcription analysis of the nifA gene, assessed using promoter deletions, indicated an oxygen-independent expression, threefold higher during symbiosis as compared with free-living conditions. Electrophoretic mobility shift assays using those nifA promoter deletion fragments, which were actively transcribed, demonstrated the specific interaction with R. etli cellular protein(s) resulting in the formation of two DNA-protein complexes. An interacting protein was purified by liquid chromatography on Heparin Sepharose and Mono S columns. The purified 12 kDa R. etli protein cross-reacted with antibodies directed against Escherichia coli integration host factor (IHF). Furthermore, purified E. coli IHF was able to specifically bind to the R. etli nifA promoter region. These results point to an as yet undisclosed function of IHF in the regulation of R. etli nifA expression.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Antibodies, Bacterial / immunology
Bacterial Proteins / genetics*
Blotting, Western
Chromatography, Affinity
Chromatography, Liquid
Cross Reactions
DNA, Bacterial / metabolism*
DNA-Binding Proteins / metabolism
Electrophoretic Mobility Shift Assay
Escherichia coli
Escherichia coli Proteins / immunology
Escherichia coli Proteins / isolation & purification
Escherichia coli Proteins / metabolism
Gene Expression Profiling
Gene Expression Regulation, Bacterial
Integration Host Factors / immunology
Integration Host Factors / isolation & purification
Integration Host Factors / metabolism*
Promoter Regions, Genetic*
Protein Binding
Rhizobium etli / genetics
Rhizobium etli / physiology*
Transcription Factors / genetics*

Substances

Antibodies, Bacterial
Bacterial Proteins
DNA, Bacterial
DNA-Binding Proteins
Escherichia coli Proteins
Integration Host Factors
NifA protein, Bacteria
Transcription Factors
integration host factor, E coli