SUI Senfang and colleagues from Tsinghua University revealed the structure of a PSI-LHCR from a red alga Cyanidioschyzon merolae by single-particle cryo-electron microscopy (cryo-EM) at a resolution of 3.63 Å. It has two forms of the PSI-LHCR supercomplex, one with 3 Lhcr antenna subunits attached (designated PSI-3Lhcr) and the other one with 5 Lhcrs subunits attached (designated PSI-5Lhcr). The 3 Lhcr subunits are associated with one side of the PSI core similar to that of the higher plant PSI, whereas the other 2 additional Lhcr subunits are attached to the opposite side in PSI-5Lhcr, indicating an ancient form of PSI-LHCI.

CAS news release, April 12, 2018