A single histidine addition to the C-terminus of PsaL of Synechocystis sp. PCC 6803 was previously reported by our lab to shift the trimer-to-monomer ratio of PSI in favor of the monomeric form. P700 re-reduction and NADP + photo-reduction measurements of the PsaL HIS strain show no effect on PSI activity in comparison to the WT trimeric PSI. Crystal structure of the PsaL HIS monomeric PSI reveals several alterations that occurred in the trimerisation site of PSI, primarily a deformation of the C-terminus of PsaL and loss of chlorophyll a and β-carotene molecules.
- Electron transport (photosynthetic)
- Membrane proteins
- Photosystem I (PSI)