Lee S H, Kim I C, Lee W S, Byun S M
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Yusong-gu, Taejon, South Korea.
FEMS Microbiol Lett. 1996 Jun 1;139(2-3):189-93. doi: 10.1111/j.1574-6968.1996.tb08201.x.
The introduction of a plasmid containing skc (streptokinase-coding gene) fused with ompA signal sequence into Escherichia coli K-12 strains, rendered the bacteria mucoid. Measurement of the synthesis of beta-galactosidase from a cps-lacZ fusion (lacZ fusion to a gene necessary for capsule synthesis) showed that the mucoid phenotype was due to induction of the capsular polysaccharide colanic acid synthesis. The introduction of a plasmid carrying skc fused with malE (gene encoding maltose-binding protein) also induced cps-lacZ expression, but intracellular expression of streptokinase in E. coli did not. The cps expression by secretion of streptokinase was diminished to the basal level in a cps-lacZ strain carrying a rcsC mutation. These results show that the secretion of streptokinase in E. coli induces colanic acid synthesis through the RcsC-dependent pathway.
将含有与ompA信号序列融合的skc（链激酶编码基因）的质粒导入大肠杆菌K-12菌株后，细菌变成了黏液状。对来自cps-lacZ融合体（lacZ与荚膜合成所需基因的融合）的β-半乳糖苷酶合成进行测量表明，黏液状表型是由于荚膜多糖柯氏酸合成的诱导。导入携带与malE（编码麦芽糖结合蛋白的基因）融合的skc的质粒也诱导了cps-lacZ表达，但大肠杆菌中链激酶的细胞内表达则没有。在携带rcsC突变的cps-lacZ菌株中，通过链激酶分泌引起的cps表达降低至基础水平。这些结果表明，大肠杆菌中链激酶的分泌通过RcsC依赖性途径诱导柯氏酸合成。
