Horinouchi M, Yamamoto T, Taguchi K, Arai H, Kudo T
RIKEN, The Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
Microbiology (Reading). 2001 Dec;147(Pt 12):3367-75. doi: 10.1099/00221287-147-12-3367.
Comamonas testosteroni metabolizes testosterone as the sole carbon source via a meta-cleavage reaction. A meta-cleavage enzyme gene, tesB, was cloned from C. testosteroni TA441. The deduced N-terminal amino acid sequence of tesB matched that of the purified meta-cleavage enzyme which is induced in TA441 during growth on testosterone as the sole carbon source. The tesB-disrupted mutant did not show growth on testosterone, suggesting that tesB is necessary for TA441 to grow on testosterone. Downstream from tesB, three putative ORFs which encode products also necessary for growth of TA441 on testosterone were identified. The usual substrate of TesB is probably 3,4-dihydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione. Although this compound was not identified in the gene disrupted mutants, accumulation of upstream metabolites of testosterone degradation, 4-androstene-3,17-dione and 1,4-androstadiene-3,17-dione, was shown by TLC analysis.
睾丸酮丛毛单胞菌通过间位裂解反应将睾酮作为唯一碳源进行代谢。从睾丸酮丛毛单胞菌TA441中克隆到一个间位裂解酶基因tesB。tesB推导的N端氨基酸序列与纯化的间位裂解酶相匹配，该酶在以睾酮作为唯一碳源生长的TA441中被诱导产生。tesB基因破坏突变体在睾酮上不生长，这表明tesB是TA441在睾酮上生长所必需的。在tesB下游，鉴定出三个假定的开放阅读框，其编码的产物也是TA441在睾酮上生长所必需的。TesB的通常底物可能是3,4-二羟基-9,10-断-雄甾-1,3,5(10)-三烯-9,17-二酮。虽然在基因破坏突变体中未鉴定出该化合物，但通过薄层层析分析表明，睾酮降解的上游代谢产物4-雄烯-3,17-二酮和1,4-雄二烯-3,17-二酮有所积累。
