Fig. 1

General scheme of sterol catabolism organisation in Actinobacteria: stages and the identified genes involved. I – initial steroid core oxidation (rings A-B), II – side chain degradation, III – deep steroid core oxidation (rings C-D). HIP – 3aα-H-4α(3′-propanoate)-7aβ-methylhexahydro-1,5-indanedione; 9,10-seco-AD – 3-hydroxy-9,10-secoandrost-1,3,5(10)-triene-9,17-dione; COCHEA-CoA – 2-(2-carboxyethyl)-3-methyl-6-oxocyclohex-1-ene-1-carboxyl-CoA; R1 – H, CH3 or C2H5 for various sterols