Fig. 3

Isoprene degradation gene clusters recovered from MAGs assembled from heavy DNA incubated with ¹³C isoprene. A, B iso clusters 1 and 2 recovered from a Mycobacterium MAG assembled from heavy DNA retrieved after DNA-SIP. Genes encoding IsoMO (isoABCDEF) are coloured in red. Adjacent genes isoGHIJ and the duplicate gene isoH2 encode a CoA transferase, dehydrogenase and two glutathione transferases involved in the subsequent steps of isoprene metabolism. Genes aldH1, CoA-DSR, gshB and marR encode an aldehyde dehydrogenase, a CoA-disulfide reductase, a glutathione synthase and a putative transcriptional regulator respectively. Adjacent genes that are not yet known to be involved in isoprene degradation are coloured in white. (696 048—Hypothetical protein; 699 065—Hypothetical protein; 699 453—Hypothetical protein; 700 611—Triacylglycerol lipase; 702 140—Acetyl-CoA-acetyltransferase; 703 826—AraC family transcriptional regulator; 226 978—Acetyl-CoA-acetyltransferase; 228 652—Hypothetical protein; 241 033—Hypothetical protein; 241 556—Hypothetical protein; 242 962—CaiB/BaiF family protein; 244 166—FAD-dependant oxidoreductase). Regulatory genes are shown in black. C A propane monooxygenase gene cluster recovered from a Mycobacterium MAG. Genes associated with propane metabolism are coloured in blue. Genes mimABCD encode an oxygenase large subunit, a reductase, an oxygenase small unit and a coupling protein respectively, making up the propane monooxygenase, with groEL encoding an associated chaperonin [75, 76]. Adjacent genes not involved in propane metabolism are coloured in grey