Fig. 7

The use of fusions to infer functions of unknown domains. a Once a fusion of an unknown with a characterized gene is discovered, the function of the latter and the clustering pattern of the fusion gene help to propose functions for the unknown gene, especially when combined with structure analysis of the unknown and the fused product. If specific compounds are bound to the unknown protein and can be associated with the metabolic area of the known enzyme, mechanisms such as channeling or repair might be inferred. The position of the known enzyme in the pathway combined with flux balance and thermodynamics analysis can give clues about the function of the unknown gene. b Examples of the application of the ModelSEED fusions exploration tool. Beveled rectangles represent the genes that participate in the fusions used as starting points for our analysis. On the beveled rectangles, Cys H stands for phosphoadenylyl-sulfate reductase (EC 1.8.4.8)/adenylyl-sulfate reductase (EC 1.8.4.10); A-B stands for acetyl-coenzyme A carboxyl transferase alpha chain (EC 6.4.1.2)/acetyl-coenzyme A carboxyl transferase beta chain (EC 6.4.1.2); NUDIX stands for Nudix_15. These genes are also identified by the same color code as the arrows that represent them in the genome sections illustrated immediately below them. The rows of arrows depict the gene clustering areas given by the SEED platform for the genes analyzed in our examples. The genes in each organism’s genome section are represented by color coded arrows and identified by letters. The functional roles represented by these letters for each organism are given in the printed section below the illustration. Examples of the stand-alone genes and their clustering patterns are also given