Figure 2

Mapping of candidate lateral gene transfer (LGTs) onto the Kyoto Encyclopedia of Genes and Genomes (KEGG) central metabolic pathways. Candidate LGTs (thick edges) were mapped on the KEGG central metabolic pathways using the tool iPath (version 2.0 [78]) which provides an overview of metabolic and other pathways annotated in KEGG. Nodes correspond to substrates and edges to enzymatic reactions. The 11 major metabolic pathways are color-coded (for example, light orange for amino acid metabolism). The LGTs are broadly distributed across pathways: all 11 major KEGG metabolic pathway categories are affected by LGTs. Note that the individual enzymes acyl-CoA dehydrogenase (EC:1.3.8.7) and acetyl-CoA C-acyltransferase (EC:2.3.1.16) each occur several times in the fatty-acid metabolism and elongation pathways, respectively (teal-colored pathways). The mapping of candidate LGTs onto the 'Biosynthesis of secondary metabolites map' and the 'Regulatory pathways or functional modules' is also illustrated (see Additional file 15).