Open AccessElectron microscopy of the Mo‐Fe‐protein from Azotobacter vinelandii nitrogenase
Author(s) -
TSUPRUN V. L.,
MITSOVA I. Z.,
BLAZHCHUK I. S.,
GVOZDEV R. I.,
ORLOVA E. V.,
KISELEV N. A.
Publication year - 1985
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1985.tb08937.x
Subject(s) - azotobacter vinelandii , nitrogenase , crystallography , azotobacter , protein quaternary structure , molecule , azotobacteraceae , electron microscope , chemistry , protein structure , protein subunit , bacteria , physics , biology , biochemistry , nitrogen fixation , nitrogen , optics , organic chemistry , gene , genetics
The quaternary structure of the Mo‐Fe‐protein from Azotobacter vinelandii has been studied by electron microscopy. A model of the molecule of the Mo‐Fe‐protein has been proposed: two α subunits are displaced relative to two β subunits along a twofold axis, so the molecule can be characterized by the point‐group pseudosymmetry 222. Computer averaging of the images showed that one of the projections of the molecule could be characterized by twofold rotational symmetry. Micrographs of nitrogenase recombined complex (Mo‐Fe‐protein + Fe‐protein) have been obtained. They showed particles close in size and form to the Mo‐Fe‐protein molecule. Therefore, it has been proposed that the Fe‐protein could be situated in the central cavity of Mo‐Fe‐protein.