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Updated: Jun 29, 2026

Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells
Published on: February 24, 2026
HtrA is essential for efficient secretion of recombinant proteins by Lactococcus lactis
Kalpana Sriraman1, Guhan Jayaraman
1Department of Biotechnology, Indian Institute of Technology-Madras, Chennai, India.
Abstract:
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.
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Inducible Operons: lac Operon
Operons

