A synthetic microbial biosensor for high-throughput screening of lactam biocatalysts. Issue 1 (December 2018)

• Record Type: Journal Article
• Authors: Yeom, Soo-Jin; Kim, Moonjeong; Kwon, Kil; Fu, Yaoyao; Rha, Eugene; Park, Sung-Hyun; Lee, Hyewon; Kim, Haseong; Lee, Dae-Hee; Kim, Dong-Myung; Lee, Seung-Goo
• Is Part Of: Nature communications. Volume 9:Issue 1(2018)
• Page Start: 1
• Page End: 12
• Publication Date: 2018-12
• Subjects: Biology -- Periodicals; Physical sciences -- Periodicals; 505
• DOI: 10.1038/s41467-018-07488-0
• Languages: English
• ISSNs: 2041-1723

Abstract

Abstract Biocatalytic cyclization is highly desirable for efficient synthesis of biologically derived chemical substances, such as the commodity chemicals ε-caprolactam and δ-valerolactam. To identify biocatalysts in lactam biosynthesis, we develop a caprolactam-detecting genetic enzyme screening system (CL-GESS). TheAlcaligenes faecalis regulatory protein NitR is adopted for the highly specific detection of lactam compounds against lactam biosynthetic intermediates. We further systematically optimize the genetic components of the CL-GESS to enhance sensitivity, achieving 10-fold improvement. Using this highly sensitive GESS, we screen marine metagenomes and find an enzyme that cyclizes ω-amino fatty acids to lactam. Moreover, we determine the X-ray crystal structure and catalytic residues based on mutational analysis of the cyclase. The cyclase is also used as a helper enzyme to sense intracellular ω-amino fatty acids. We expect this simple and accurate biosensor to have wide-ranging applications in rapid screening of new lactam-synthesizing enzymes and metabolic engineering for lactam bio-production. Efficient biosynthesis of lactams is still undesirable due to lacking of suitable enzyme. Here, the authors develop a sensitive transcription factor-based biosensor for high-throughput screening of marine metagenome and find a cyclase that can cyclize ω-amino fatty acids to lactam.