Open AccessnifV-dependent, low-molecular-weight factor required for in vitro synthesis of iron-molybdenum cofactor of nitrogenase
Author(s) -
Timothy R. Hoover,
Vinod K. Shah,
Gary P. Roberts,
Paul W. Ludden
Publication year - 1986
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.167.3.999-1003.1986
Subject(s) - azotobacter vinelandii , nitrogenase , sephadex , biochemistry , biology , size exclusion chromatography , azotobacteraceae , cofactor , azotobacter , klebsiella pneumoniae , molybdenum , microbiology and biotechnology , bacteria , chromatography , nitrogen fixation , chemistry , inorganic chemistry , escherichia coli , enzyme , genetics , gene
The molybdate- and ATP-dependent in vitro synthesis of the iron-molybdenum cofactor of nitrogenase requires a low-molecular-weight factor. The factor is present in extracts of nitrogen fixation-derepressed cultures of Klebsiella pneumoniae and Azotobacter vinelandii, but not in extracts of repressed cultures of these bacteria. Analysis of K. pneumoniae Nif mutants has indicated that the nifV gene product is the only nif protein (besides nifA) necessary for the synthesis and accumulation of the factor. The factor is stable to oxygen, temperatures below 120 degrees C, and extremely acidic and basic conditions. The activity of the factor was completely destroyed by dry ashing or digestion with sulfuric acid. The factor has been partially purified by filtration through an Amicon PM-10 DIAFLO membrane and chromatography on DEAE-cellulose, hydroxylapatite, silica gel, and Sephadex G-25.