The lability of Rubisco activase function is thought to have a major role in the decline of leaf photosynthesis under moderate heat (<35°C). To investigate this further, we characterized Rubisco activase and explored its role in the previously demonstrated thermal acclimation and inhibition of two genotypes of Acer rubrum originally collected from Florida (FL) and Minnesota (MN). When plants we...

1. The roles of ubiquinone-IO and of rhodoquinone in photosynthetic ATP formation were studied with chromatophores from a blue-green mutant (G-9) of Rhodospirillum rubrum. 2. Chromatophores contained ubiquinone-10 and rhodoquinone in amounts equal approximately to 50% and lo%, respectively, on a molar basis, of that of bacteriochlorophyll. Other quinones were not present in appreciable amounts....

Rhodospirillum rubrum is a facultatively phototrophic bacterium that, under certain growth conditions, forms an intracytoplasmic chromatophore membrane (ICM) housing the photochemical apparatus. The puf operon of R. rubrum encodes protein subunits of the photochemical reaction center and the B880 light-harvesting antenna complex. Mutant strains of R. rubrum were constructed by interposon mutage...

Heterologous expression of a bacterial light-harvesting (LH) integral membrane protein was attempted using Escherichia coli cells and cell-free synthesis systems prepared from E. coli extracts. The alpha-apoprotein of LH1 complex from purple photosynthetic bacterium Rhodospirillum rubrum was overexpressed as a recombinant protein with a histidine (His6) tag added to the carboxyl terminus. Both ...

The quantum yield and lifetimes of fluorescence and triplet state of the B820 subunit of core antenna of photosynthetic purple bacterium Rhodospirillum rubrum are reported at temperature range from 4.2 to 300K. The fluorescence quantum yield of B820 is strongly dependent on temperature. From 4.2 to about 200 K the yield remains nearly constant. A nonradiative decay process becomes activated aro...

The photosynthetic non-sulphur bacterium Rhodospirillum rubrum contains a cluster of five genes encoding the subunits of F1-ATPase [Falk, Hampe & Walker (1985) Biochem. J. 228, 391-407]. Transcription of these genes has been studied by two methods, transcriptional mapping with S1 nuclease and primer extension analysis. Thereby a 5'-end in RNA derived from this region has been demonstrated at a ...

The sequences proposed in Fig. 1 for the Ps. aerirgirioJa and Ps. strrtzeri proteins have been confirmed by the isolation and characterization of the expected peptides from tryptic digests of the haeni-free proteins. From each of these two proteins a second tryptic peptide was isolated that contained two residues of cysteine and a residue of histidine. The amino acid composition was such that t...

Reconstituted LH1 complexes were prepared using the LH1 subunit-type complexes, isolated from the purple photosynthetic bacterium Rhodospirillum (Rs.) rubrum, and purified all-trans spirilloxanthin. Stark absorption spectra of spirilloxanthin bound to both the native and reconstituted LH1 complexes were compared in different polarization angles (χ) against the external electric field. From the ...

A stoichiometric unit of the light-harvesting complex I and the reaction centre (LHI-RC complex) has been isolated from a carotenoid-less mutant of the purple non-sulphur bacterium Rhodospirillum rubrum by mild solubilization of photosynthetic membranes with the phospholipid detergent diheptylphosphatidylcholine. Dialysis of the isolated LHI-RC complexes in the presence of added dioleoyl-sn-pho...