Fig. 4

Putative carbon fixation pathway in H. rowanensis. Enzymes: 1 = phosphoenolpyruvate synthase; 2 = phosphoenolpyruvate carboxylase; 3 = malate dehydrogenase; 4 = fumarate hydratase; 5 = succinate dehydrogenase; 6 = succinyl-CoA ligase; 6a = γ-butyrobetaine,2-oxoglutarate dioxygenase; 7 = 2-oxoglutarate synthase; 8 = Isocitrate dehydrogenase [NADP]; 9–10 = aconitate hydratase; 11 = citrate lyase and 12 = NADP-dependent malic enzyme. Metabolites: PEP = phosphoenolpyruvate; αKG = α-ketoglutarate; 3-OHTMAB = 3-hydroxy-4-trimethylammoniobutanoate and 4-TMAB = 4-trimethylammoniobutanoate. Gene annotation was performed using a combined approach with Rapid Annotations using Subsystems Technology toolkit (RASTtk) along with BLASTp validation, using the KEGG carbon fixation pathways as guide for enzyme discovery. EC numbers for each enzyme can be found in Additional file 1: Table S3