The nucleotide sequence of the puf operon from the purple photosynthetic bacterium, Rhodospirillum molischianum: Comparative analyses of light-harvesting proteins and the cytochrome subunits associated with the reaction centers

1996 ◽  
Vol 50 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Kenji V. P. Nagashima ◽  
Katsumi Matsuura ◽  
Keizo Shimada
Keyword(s):  
Nucleotide Sequence ◽  
Light Harvesting ◽  
Photosynthetic Bacterium ◽  
Reaction Centers ◽  
Comparative Analyses ◽  
Puf Operon ◽  
Purple Photosynthetic Bacterium ◽  
Rhodospirillum Molischianum

Reduction of the oxidized bacteriochlorophyll dimer in reaction centers by ferrocene is dependent upon the driving force

2007 ◽  
Vol 11 (03) ◽  
pp. 205-211 ◽  
Author(s):  
László Kálmán ◽  
Arlene L. M. Haffa ◽  
JoAnn C. Williams ◽  
Neal W. Woodbury ◽  
James P. Allen
Keyword(s):  
Electron Transfer ◽  
Rate Constants ◽  
Ph Dependence ◽  
Photosynthetic Bacterium ◽  
Energy Difference ◽  
Reaction Centers ◽  
Free Energy Difference ◽  
Midpoint Potential ◽  
Bacteriochlorophyll Dimer ◽  
Purple Photosynthetic Bacterium

The rates of electron transfer from ferrocene to the oxidized bacteriochlorophyll dimer, P , in reaction centers from the purple photosynthetic bacterium Rhodobacter sphaeroides, were measured for a series of mutants in which the P / P + midpoint potentials range from 410 to 765 mV (Lin et al. Proc. Natl. Acad. Sci. USA 1994; 91: 10265-10269). The observed rate constant for each mutant was found to be linearly dependent upon the ferrocene concentration up to 50 μM. The electron transfer is described as a second order reaction with rate constants increasing from 1.5 to 35 × 106 M -1. s -1 with increasing P / P + midpoint potential. This dependence was tested for three additional mutants, each of which exhibits a pH dependence of the P / P + midpoint potential due to an electrostatic interaction with an introduced carboxylic group (Williams et al. Biochemistry 2001; 40: 15403-15407). For these mutants, the pH dependence of the bimolecular rate constants followed a sigmoidal pattern that could be described with a Henderson-Hasselbalch equation, attributable to the change of the free energy difference for the reaction due to deprotonation of the introduced carboxylic side chains.

scholarly journals The light intensity under which cells are grown controls the type of peripheral light-harvesting complexes that are assembled in a purple photosynthetic bacterium

2011 ◽  
Vol 440 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Tatas H. P. Brotosudarmo ◽  
Aaron M. Collins ◽  
Andrew Gall ◽  
Aleksander W. Roszak ◽  
Alastair T. Gardiner ◽  
...  
Keyword(s):  
Light Intensity ◽  
Light Harvesting ◽  
Rhodopseudomonas Palustris ◽  
Photosynthetic Bacterium ◽  
Low Light ◽  
Light Harvesting Complexes ◽  
Density Maps ◽  
Purple Photosynthetic Bacterium ◽  
Resonance Raman Spectra ◽  
Apoprotein Composition

The differing composition of LH2 (peripheral light-harvesting) complexes present in Rhodopseudomonas palustris 2.1.6 have been investigated when cells are grown under progressively decreasing light intensity. Detailed analysis of their absorption spectra reveals that there must be more than two types of LH2 complexes present. Purified HL (high-light) and LL (low-light) LH2 complexes have mixed apoprotein compositions. The HL complexes contain PucABa and PucABb apoproteins. The LL complexes contain PucABa, PucABd and PucBb-only apoproteins. This mixed apoprotein composition can explain their resonance Raman spectra. Crystallographic studies and molecular sieve chromatography suggest that both the HL and the LL complexes are nonameric. Furthermore, the electron-density maps do not support the existence of an additional Bchl (bacteriochlorophyll) molecule; rather the density is attributed to the N-termini of the α-polypeptide.

scholarly journals Reconstitution of 3-Acetyl Chlorophyll a into Light-Harvesting Complex 2 from the Purple Photosynthetic Bacterium Phaeospirillum molischianum

ACS Omega ◽  
2020 ◽  
Vol 5 (12) ◽  
pp. 6817-6825 ◽  
Author(s):  
Yoshitaka Saga ◽  
Madoka Yamashita ◽  
Michie Imanishi ◽  
Yukihiro Kimura ◽  
Yuto Masaoka ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Light Harvesting ◽  
Photosynthetic Bacterium ◽  
Light Harvesting Complex ◽  
Purple Photosynthetic Bacterium
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