Gr. Wolfe et al., EVIDENCE FOR A COMMON ORIGIN OF CHLOROPLASTS WITH LIGHT-HARVESTING COMPLEXES OF DIFFERENT PIGMENTATION, Nature, 367(6463), 1994, pp. 566-568
THE red algae (Rhodophyta), which like cyanobacteria have only chlorop
hyll a and use phycobilisomes for light-harvesting1,2, are often consi
dered to have originated independently of other photosynthetic eukaryo
tes, namely the chlorophyll a/b-containing Chlorophyta and the chlorop
hyll a/c-containing Chromophyta3. Here we report that the red alga Por
phyridium cruentum has a chlorophyll a-containing antenna complex func
tionally associated with photosystem I, and that polypeptides of this
antenna complex are immunologically related to those of higher-plant c
hlorophyll a/h complexes and to those of chromophyte fucoxanthin-chlor
ophyll a/c antenna complexes. This establishes a clear link between or
ganisms containing phycobilisomes and those containing chlorophyll-bas
ed light-harvesting complexes and shows that these antennae can co-exi
st in the same organism. Furthermore, it suggests that the light-harve
sting proteins of all photosynthetic eukaryotes had a common origin an
d supports the idea that chloroplasts had a common ancestor4-6.