title: [Investigation of the structure of nitrogenase by means of electron microscopy combined with optical diffraction].
abstract: Nitrogenase molecules are observed in electron micrographs as hepta or octa hedral rings about 100 angstrom in diameter and stick-like particle 95 angstrom wide and as long as 300 angstrom and more. The electron microscopy pattern was investigated by the optical diffraction technique. It is shown that the nitrogenase molecule has a cylindrical helical structure. The helical parameters of this structure have been determined. The molecule is composed of a family of discrete helixes (number of helixes 8), the spacing between the nearest subunits along the vertical axis being 25 angstrom and the period of the structure about 50 angstrom. It is supposed that the stick-like particle as a side-view projection of the polymerized round molecules. A hypothetic model of the protein is presented.
mesh_terms: D003461:Crystallography; D008854:Microscopy, Electron; D008958:Models, Molecular; D009591:Nitrogenase; D011487:Protein Conformation
chemical_list: D009591:Nitrogenase
vernacular_title: Issledovanie struktury nitrogenazy metodom elektronnoĭ mikroskopii i opticheskoĭ difraktsii.