Sriraman Kalpana, Jayaraman Guhan
Department of Biotechnology, Indian Institute of Technology-Madras, Chennai, India.
Appl Environ Microbiol. 2008 Dec;74(23):7442-6. doi: 10.1128/AEM.00638-08. Epub 2008 Oct 3.
HtrA is a unique protease on the extracellular surface of Lactococcus lactis. It is known to take part in the proteolysis of many secreted recombinant proteins, and the mutation of htrA can lead to the complete stabilization of recombinant proteins. In this work, we have shown that htrA mutation also leads to significant reduction of the efficiency of recombinant-protein secretion. We also show that the level of HtrA can be lowered by the suppression of the acid tolerance response (ATR) in L. lactis. Instead of using an L. lactis htrA mutant, the reduction of the HtrA level in wild-type recombinant cultures of L. lactis by ATR suppression may serve as a better strategy for the production of secreted recombinant proteins.
HtrA是乳酸乳球菌细胞外表面的一种独特蛋白酶。已知它参与许多分泌型重组蛋白的蛋白水解，htrA的突变可导致重组蛋白完全稳定。在这项工作中，我们已经表明htrA突变也会导致重组蛋白分泌效率显著降低。我们还表明，通过抑制乳酸乳球菌的耐酸反应（ATR）可以降低HtrA的水平。通过ATR抑制降低野生型乳酸乳球菌重组培养物中HtrA的水平，而不是使用乳酸乳球菌htrA突变体，可能是生产分泌型重组蛋白的更好策略。
