3D-Structure-Function
of Light-harvesting Protein of Algae and the Transmission
of Light Energy
Under the support of the Key Program project of
NSFC, CAS Member Liang Dongcai and colleagues
of CAS Institute of Biophysics has studied the
mechanism of light transfer in the light harvesting
system of photosynthesis organisms. Through many
years of efforts, they have successively finished
the 3d-structure of R-Phycoerythrin in 2.8Å and 1.9Å resolution (J.Mol.Biol. (1996) 262,721-731;
Proteins (1999) 34:224-231), R-Phycoerythrin
in 2.4Å trdoluyion (Biophysical Journal
(2001)) and Allophycocyanin in 2.2Å resolution
(Acta Cryst. (1998) D54, 662-664; J.Biol.Chem.
(1999) 274, 16945-16952) research, and they have
given detailed studies on their functions They
have brought forward the model of energy transferring
within the Phycoerythrin and the possible energy
transfer route between Phycoerythrin and near
phycocyanin. They discovered that the function
unit of Allophycocyanin is "loose hexamer",
but is not the world commonlyecognized trimer.
Through systematic studies, Prof. Liang and his
colleagues developed the model of the energy transfer
route within phycobillisome. This has established
an important structural basis for elucidating
the mechanism of energy transferring in the light
harvesting system in algae.
Sketch map of Ca atom of R-Phycoerythrin hexamer
and pigment molecular in 1.9Å resolution, indicated
by three independent parts in red, green and blue
by axe-connection three times. The oxygen atom
of pigment molecules is in red, carbon atom in
yellow and nitrogen atom in blue.
Molecule stack map of R-phycocyanin in crystal
cells. The yellow and blue color indicate two
different tightly stacked trimer (αβ)3 of R-phycocyanin,
compared with other Biliproteins in crystal cells,
and its cumuli method is quite typical.
Sketch map of the route of energy transfer within
R-Phycoerythrin. The four phycoerythrobilins connecting
α84, β84, α140a and cysteine inβ155 position are
in green color, the simultaneity connected pyhcourobilin
with cysteine inβ50 and β61 cysteine is in pink.
Sketch
map of ribbon of αsub-unit, βsub-unit of Allophycocyanin
(left) and trimer (right). αsub-unit is indicated
in green and βsub-unit in blue. The oxygen atom
of pigment molecular is indicated in red balls,
carbon atom in yellow balls and nitrogen atom
in blue balls.
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