Suvorova M M, Solianikova I P, Golovleva L A
Pushchino State University, Pushchino, Moscow Region, 142290, Russia.
Biochemistry (Mosc). 2006 Dec;71(12):1316-23. doi: 10.1134/s0006297906120054.
Degradation of para-toluate by Rhodococcus opacus 1cp was investigated. Activities of the key enzymes of this process, catechol 1,2-dioxygenase and muconate cycloisomerase, are detected in this microorganism. Growth on p-toluate was accompanied by induction of two catechol 1,2-dioxygenases. The substrate specificity and physicochemical properties of one enzyme are identical to those of chlorocatechol 1,2-dioxygenase; induction of the latter enzyme was observed during R. opacus 1cp growth on 4-chlorophenol. The other enzyme isolated from the biomass grown on p-toluate exhibited lower rate of chlorinated substrate cleavage compared to the catechol substrate. However, this enzyme is not identical to the catechol 1,2-dioxygenase cloned in this strain within the benzoate catabolism operon. This supports the hypothesis on the existence of multiple forms of dioxygenases as adaptive reactions of microorganisms in response to environmental stress.
研究了不透明红球菌1cp对对甲苯酸盐的降解情况。在这种微生物中检测到了该过程关键酶儿茶酚1,2 -双加氧酶和粘康酸环异构酶的活性。在对甲苯酸盐上生长伴随着两种儿茶酚1,2 -双加氧酶的诱导。其中一种酶的底物特异性和理化性质与氯儿茶酚1,2 -双加氧酶相同；在不透明红球菌1cp在4 -氯苯酚上生长期间观察到了后一种酶的诱导。从在对甲苯酸盐上生长的生物量中分离出的另一种酶与儿茶酚底物相比，对氯化底物的裂解速率较低。然而，这种酶与在该菌株苯甲酸分解代谢操纵子中克隆的儿茶酚1,2 -双加氧酶不同。这支持了关于双加氧酶存在多种形式作为微生物对环境压力的适应性反应的假设。
