Cooper T G, McKelvey J, Sumrada R
J Bacteriol. 1979 Sep;139(3):917-23. doi: 10.1128/jb.139.3.917-923.1979.
Oxalurate, the gratuitous inducer of the allantoin degradative enzymes, was taken into the cell by an energy-dependent active transport system with an apparent Km of 1.2 mM. Efflux of previously accumulated oxalurate was rapid, with a half-life of about 2 min. The oxalurate uptake system appears to be both constitutively produced and insensitive to nitrogen catabolite repression. The latter observations suggest that failure of oxalurate to bring about induction of allophanate hydrolase in cultures growing under repressive conditions does not result from inducer exclusion, but rather from repression of dur1,2 gene expression.
草尿酸盐是尿囊素降解酶的 gratuitous 诱导剂，通过一个表观 Km 为 1.2 mM 的能量依赖型主动转运系统进入细胞。先前积累的草尿酸盐外流迅速，半衰期约为 2 分钟。草尿酸盐摄取系统似乎是组成型产生的，并且对氮分解代谢物阻遏不敏感。后一观察结果表明，在抑制条件下生长的培养物中，草尿酸盐未能诱导脲基甲酸水解酶，这不是由于诱导剂排除，而是由于 dur1,2 基因表达受到抑制。
