Nitrogenase from the photosynthetic bacterium Rhodopseudomonas capsulata: purification and molecular properties

Journal Article · Mon Feb 01 04:00:00 EST 1982 · J. Bacteriol.; (United States)

OSTI ID:5103192

Hallenbeck, P C; Meyer, C M; Vignais, P M

Nitrogenase proteins were isolated from cultures of the photosynthetic bacterium Rhodopseudomonas capsulata grown on a limiting amount of ammonia. Under these conditions, the nitrogenase N/sub 2/ase A was active in vivo, and nitrogenase activity in vitro was not dependent upon manganese and the activating factor. The nitrogenase proteins were also isolated from nitrogen-limited cultures in which the in vivo nitrogenase activity had been stopped by an ammonia shock. This nitrogenase activity, N/sub 2/ase R, showed an in vitro requirement for manganese and the activating factor for maximal activity. The Mo-Fe protein (dinitrogenase) was composed of two dissimilar subunits with molecular weights of 55,000 and 59,500; the Fe protein (dinitrogenase reductase), from either type of culture, was composed of a single subunit (molecular weight, 33,500). The metal and acid labile sulfur contents of both nitrogenase proteins were similar to those found for previously isolated nitrogenases. The Fe proteins from both N/sub 2/ase a and N/sub 2/ase R contained phosphate and ribose, 2 mol of each per mol of N/sub 2/ase R Fe protein contained about 1 mol per mol of an adenine-like molecule, whereas the N/sub 2/ase A Fe protein content of this compound was insignificant. These results are compared with various models previously presented for the short-term regulation of nitrogenase activity in the photosynthetic bacteria.

• Research Organization: Centre d'Etudes Nucleaires, Grenoble, France
• OSTI ID: 5103192
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 149:2; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505 -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
550200 -- Biochemistry
550700* -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
CHEMICAL COMPOSITION
ELEMENTS
ENZYME ACTIVITY
ENZYMES
IRON
MANGANESE
METALS
MICROORGANISMS
MOLECULAR WEIGHT
NITRO-GROUP DEHYDROGENASES
NITROGENASE
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PHOTOSYNTHETIC BACTERIA
PROTEINS
PURIFICATION
RHODOPSEUDOMONAS
TRANSITION ELEMENTS