Enzymes of the reductive pentose phosphate cycle including ribulose-diphosphate carboxylase, ribulose-5-phosphate kinase, ribose-5-phosphate isomerase, aldolase, glyceraldehyde-3-phosphate dehydrogenase and alkaline fructose-1,6-diphos-phatase were shown to be present in autotrophically grown Rhodospirillum rubrum. Enzyme levels were measured in this organism grown photo- and dark heterotrophic...

Threonine deaminase from Rhodospirillum rubrum is subject to reversible cold inactivation a t low protein concentrations. The inactivation appears to involve a dissociation of the native tetrameric protein to dimers. The standard free energy of dissociation a t 0 "C was + 7.8 kcal/mole, while A H was 3.2 kcal/mole and AX was 41 entropy units. These values suggest that hydrophobic interactions a...

Rhodospirillum rubrum and Rhodobacter sphaeroides were shown to be capable of photolithoautotrophic growth in the absence of the reductive pentose phosphate (Calvin) cycle. Ribulose 1,5-bisphosphate carboxylase-oxygenase (RubisCO) deletion strains were incapable of photolithoautotrophic growth using hydrogen as an electron donor but were able to grow in the absence of organic carbon using less ...

The catalysis of the energy-linked transhydrogenation reaction of Rhodospirillum rubrum chromatophores is dependent upon a soluble protein, the transhydrogenase factor. This factor can be detached from the chromatophore membrane by the relatively mild procedures of extensive washing, passage of chromatophores through Sephadex G-ZOO, or sedimentation of chromatophores through a dense sucrose sol...