Fig. 2.

The c.749A > G (p.E263G) mutation lies within a conserved region of the SUCLG1 protein. A.) Evolutionary conservation of the p.E263 from zebrafish to human. B.) Ribbon representation of human succinyl-CoA synthetase active site modeled with GTP and CoA. The α-subunit encoded by SUCLG1 gene is colored in green and the β-subunit encoded by SUCLG2 gene in light blue. The molecule of GTP, CoA, p.E263 and p.H299 is represented by a ball-stick model. The p.E263 residue is annotated in red font and its position is circled with a dashed line. The hydrogen bonding network is illustrated by the yellow dashed lines surrounding p.E263 and the water molecule colored in cyan. The p.E257 residue interacts directly with the catalytic residue p.H299, and the main chain oxygen atom of p.E257 is hydrogen bonded to the side chain of p.E263 and the water molecule.