Premium
Expression and functional analysis of an N‐truncated NifA protein of Herbaspirillum seropedicae
Author(s) -
Monteiro R.A,
Souza E.M,
Funayama S,
Yates M.G,
Pedrosa F.O,
Chubatsu L.S
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00314-2
Subject(s) - escherichia coli , fusion protein , lac operon , activator (genetics) , biology , gene , footprinting , microbiology and biotechnology , promoter , biochemistry , chemistry , gene expression , transcription factor , recombinant dna
In Herbaspirillum seropedicae , an endophytic diazotroph, nif gene expression is under the control of the transcriptional activator NifA. We have over‐expressed and purified a protein containing the central and C‐terminal domains of the H. seropedicae NifA protein, N‐truncated NifA, fused to a His‐Tag sequence. This fusion protein was found to be partially soluble and was purified by affinity chromatography. Band shift and footprinting assays showed that the N‐truncated NifA protein was able to bind specifically to the H. seropedicae nifB promoter region. In vivo analysis showed that this protein activated the nifH promoter of Klebsiella pneumoniae in Escherichia coli only in the absence of oxygen and this activation was not negatively controlled by ammonium ions.