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

Tatas Hardo Panintingjati Brotosudarmo , Aaron M. Collins , Andrew Gall , Aleksander W. Roszak , Alastair T. Gardiner , Robert E Blankenship , Richard John Cogdell (1)

1 Institute of Molecular Cell and System Biology

The differing composition of peripheral light harvesting complexes (LH2) present in Rhodopseudomonas (Rps.) palustris 2.1.6 have been investigated when cells are grown at progressively decreasing light intensity. Detailed analysis of their absorption spectra reveals that there must be more than two types of LH2 complexes present. Purified high-light (HL) and low-light (LL) 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 apopotein composition can explain their resonance Raman spectra. Crystallographic studies and molecular sieve chromatography suggest that both the HL and the LL complexes are nonameric.

Mots clés: Life Sciences

Tatas Hardo Panintingjati Brotosudarmo, Aaron M. Collins, Andrew Gall, Aleksander W. Roszak, Alastair T. Gardiner, et al.. The light intensity at which cells are grown controls the type of peripheral light-harvesting complexes that are assembled in a purple photosynthetic bacterium. Biochemical Journal, 2011, 440 (1), pp.51-61. ⟨10.1042/BJ20110575⟩. ⟨hal-00642834⟩