Testosterone degradation genes in Comamonas testosteroni TA441 II: ORF12 and tesD, E, F, G

A meta-cleavage enzyme gene, tesB, was cloned from Comamonas testosteroni TA441. The tesB-disrupted mutant did not grow on testosterone, suggesting that tesB is necessary for TA441 growth on testosterone. The usual substrate of TesB is probably 3,4-dihydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione. By analyzing the transposon mutants of TA441 that show limited growth on testosterone, tesD, which encodes a hydrolase that probably acts on the meta-cleavage compound produced by TesB, was identified. Downstream of tesD, tesE, F, and G, which encode three enzymes that share 60–85% identity with BphH, J, I, respectively, were identified. TesE, F, and G are thought to degrade 2-hydroxyhexa-2,4-dienoic acid during testosterone degradation in TA441 cells.