Fig. 3: Taurine and DMSP metabolic pathways identified and expressed in ‘Ca. Taurinisymbion ianthellae’.

Central carbon and nitrogen metabolism in ‘Ca. Taurinisymbion ianthellae’ based on metaproteogenomic analyses with a focus on taurine and DMSP metabolism pathways along with the relevant import and export of exchanged metabolites. Depicted are proteins necessary for taurine import, followed by taurine dissimilation, energy conservation via sulfite oxidation and the electron transport chain, along with carbon incorporation via the glyoxylate bypass. Similarly depicted are the proteins necessary for DMSP import as well as the corresponding DMSP cleavage and demethylation pathways, including the oxidation of 5-methyl-THF and its role as a carbon donor for the conversion of glycine to serine. Enzymes detected via metaproteomics are highlighted in fuchsia, while enzymes only identified in the ‘Ca. Taurinisymbion ianthellae’ MAG are highlighted in turquoise. Missing pathway genes are depicted as white shapes. AMP adenosine monophosphate, APS adenosine-5’-phosphosulfate, Cys cysteine, DMSP dimethylsulfoniopropionate, DMS dimethylsulfide, 3-HP 3-hydroxypropanoate, Met methionine, MMPA methylmercaptopropionate, MTA-CoA methylthioacryloyl-Coenzyme A, PEP phosphoenolpyruvate, PLP pyridoxal 5’-phosphate, Q quinone, ThDP thiamine diphosphate, THF tetrahydrofolate. Additional information for genes and pathways depicted in the figure can be found in Supplementary Tables S2–S5.