This model includes both mitochondrial and peroxisomal forms of citrate synthase. Citrate synthase is the entry point to the TCA cycle from acetyl-CoA. Peroxisomal forms, such as SP:P08679 from yeast (recognized by the C-terminal targeting motif SKL) act in the glyoxylate cycle. Eukaryotic homologs excluded by the high trusted cutoff of this model include a Tetrahymena thermophila citrate synthase that doubles as a filament protein, a putative citrate synthase from Plasmodium falciparum (no TCA cycle), and a methylcitrate synthase from Aspergillus nidulans.