Extended Data Fig. 7: Citrate synthase evolved from an ancestral CCL module.
From: Structure of ATP citrate lyase and the origin of citrate synthase in the Krebs cycle
a, Side-by-side comparison and overlay of the helical bundle cores of H. thermophilus CCL and P. furiosus CS (PDB accession 1AJ8). b, Two adjacent CCL protomers (CCL and CCL’) extracted from the H. thermophilus CCL tetramer. c, A CS protomer extracted from P. furiosus CS. d, CCL without its CoA-binding domain (residues 2–100 and 204–231) aligned with the N-terminal half of CS (residues 6–143). e, CCL’ (residues 30–256) aligned with the C-terminal half of CS (residues 154–376). f, CCL and CCL’ aligned with the CS protomer. g, Sequence alignment between CCL and CCL’ and CS sequences. Top secondary structure elements correspond to H. thermophilus CCL and CCL’, bottom secondary structures correspond to P. furiosus CS. The active site residues of CS are indicated by a purple arrow. h, i, Details of the overlay between CCL and CCL’ and the CS protomer. j, Side view of the CCL module and CS highlighting the pseudo-two-fold symmetry in the CS protomer. CoA is shown by sticks.
