Protein phosphorylation in Rhodospirillum rubrum: Further characterization of the B873 kinase activity

Kinetics of in vivo bacteriochlorophyll fluorescence yield and the state of photosynthetic apparatus of purple bacteria

“…If one assumes that the maximal membrane potential reached is about 150 mV, this yields about 1.5% change of F(P 870 Q A -)/F o per 10 mV, which corresponds exactly to value given for chromatophores by Steiger and Sauer (1995). As for the rather high F(P 870 Q A -)/F o value, we refer to works of Holmes and Allen (1986) and Ghosh et al (1994), who, after subjecting bacterial samples to low redox potential, observed significantly decreased phosphorylation of the antenna complexes, which brought about an increase of the fluorescence yield. Thus, one would expect that in untreated samples, the k A-value computed using the above-described approach would be higher.…”

“…It was shown that in Rhodospirillum (Rsp.) rubrum, phosphorylation of LHI subunits regulates excitonic cooperativity, the efficiency of energy transfer from antenna to the RC and consequently the fluorescence yield (Holmes and Allen 1986;Ghosh et al 1994). Several researchers have stated that the fluorescence yield in purple bacteria is influenced by the membrane potential.…”

Phosphorylation of the α and β polypeptides of the light-harvesting complex I (B870) of Rhodobacter capsulatus in an in vitro translation system

“…It is also a widespread mechanism to control the distribution of excitation energy in chloroplast thylakoids [3]. Phosphorylation of light-harvesting (LH) proteins in membranes of photosynthetic bacteria has been described as well [4][5][6][7][8]10]. Protein phosphorylation was correlated with changes of cooperativity of the LH-system, monitored by measurements of transients of bacteriochlorophyll (BChl) fluorescence yield [5,8].…”

“…Phosphorylation of light-harvesting (LH) proteins in membranes of photosynthetic bacteria has been described as well [4][5][6][7][8]10]. Protein phosphorylation was correlated with changes of cooperativity of the LH-system, monitored by measurements of transients of bacteriochlorophyll (BChl) fluorescence yield [5,8]. The extent of phosphorylation is dependent on the redox state of the quinone pool, which seems to affect the kinase directly [3,7,8].…”

“…Protein phosphorylation was correlated with changes of cooperativity of the LH-system, monitored by measurements of transients of bacteriochlorophyll (BChl) fluorescence yield [5,8]. The extent of phosphorylation is dependent on the redox state of the quinone pool, which seems to affect the kinase directly [3,7,8]. In Rhodobacter capsulatus the LHIa polypeptide was the only phosphorylated protein of the photosynthetic apparatus [7].…”