Extended Data Fig. 3: Lhca3 chlorophyll a 614 can handily diffuse out of PSI structure due to weak binding.
From: The structure of a triple complex of plant photosystem I with ferredoxin and plastocyanin
a, Chlorophyll a 614 amino acid and ligands in its local environment in Lhca3. Proximal ligands include chlorophyll a 606 and β-carotene 503. Ligands are coloured green and amino acids carbons coloured orange, oxygens in red and nitrogens in blue. PSI subunits are shown as cartoon, view and colours are the same as in Fig. 1. b, Zoom in on chlorophyll a 614 shows neither it nor chlorophyll a 606 magnesium ions are coordinated by an amino acid. Chlorophyll a 614 can readily diffuse from Lhca3 after membrane solubilization (as previously reported46), while chlorophyll a 606 is covered by β-carotene 503 and lutein 502, stabilizing its binding to Lhca3 polypeptide chain. The amino acids close to chlorophyll a 606 are Gly115, Ala118 and Pro119, while Ile128, Pro129 and Thr132 are adjacent to chlorophyll a 614. c, Map density of chlorophyll a 614 from a top and side view.
