Mulrooney S B, Pankratz H S, Hausinger R P
Department of Biochemistry, Michigan State University, East Lansing 48824.
J Gen Microbiol. 1989 Jun;135(6):1769-76. doi: 10.1099/00221287-135-6-1769.
The genes for Klebsiella aerogenes (K. pneumoniae) urease were cloned and the protein was overexpressed (up to 18% of total protein consisted of this enzyme) in several hosts. The small size of the DNA encoding urease (3.5 kb), the restriction map, and the regulation of enzyme expression directed by the recombinant plasmid are distinct from other cloned ureases. Nickel concentration did not affect urease gene expression, as demonstrated by the high levels of apoenzyme measured in cells grown in nickel-free media. However, nickel was required for urease activity. The overproducing recombinant strain was used for immunogold electron microscopic localization studies to demonstrate that urease is a cytoplasmic enzyme.
产气克雷伯菌（肺炎克雷伯菌）脲酶基因被克隆出来，该蛋白在多个宿主中实现了过表达（该酶占总蛋白的比例高达18%）。编码脲酶的DNA片段较小（3.5 kb），其限制酶切图谱以及重组质粒指导的酶表达调控与其他已克隆的脲酶不同。镍浓度并不影响脲酶基因的表达，这一点在无镍培养基中生长的细胞中测得的大量脱辅基酶蛋白得到了证明。然而，镍对于脲酶活性是必需的。过量表达的重组菌株被用于免疫金电子显微镜定位研究，以证明脲酶是一种胞质酶。
