title: Functional participation of a nifH-arsA2 chimeric fusion gene in arsenic reduction by Escherichia coli.
abstract: The NifH (dimer) and ArsA proteins are structural homologs and share common motifs like nucleotide-binding domains, signal transduction domains and also possible similar metal center ligands. Given the similarity between two proteins, we investigated if the NifH protein from Azotobacter vinelandii could functionally substitute for the ArsA1 half of the ArsA protein of Escherichia coli. The chimeric NifH-ArsA2 protein was expressed and detected in the E. coli strain by Western blotting. Growth comparisons of E. coli strains containing plasmids encoding for complete ArsA, partial ArsA (ArsA2) or chimeric ArsA (NifH-ArsA2) in media with increasing sodium arsenite concentrations (0-5 mM) showed that the chimeric NifH-ArsA2 could substitute for the ArsA. This functional complementation demonstrated the strong conservation of essential domains that have been maintained in NifH and ArsA even after their divergence to perform varied functions.
authors.affiliation: Department of Biological Sciences, Mississippi State University, P.O. Box GY, Mississippi State, MS 39762, USA.
authors.forename: Surobhi
authors.initials: S
authors.lastname: Lahiri
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Pulakat
authors.forename: Nara
authors.initials: N
authors.lastname: Gavini
mesh_terms: D001151:Arsenic / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D016623:Ion Pumps / Q000235:genetics / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods; D011993:Recombinant Fusion Proteins / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D016623:Ion Pumps; D009097:Multienzyme Complexes; D011993:Recombinant Fusion Proteins; D010088:Oxidoreductases; C029130:nitrogenase reductase; C486481:ArsAB ATPase, E Coli; D001151:Arsenic