5yss

Publication Abstract from PubMed

Biocatalytic cyclization is highly desirable for efficient synthesis of biologically derived chemical substances, such as the commodity chemicals epsilon-caprolactam and delta-valerolactam. To identify biocatalysts in lactam biosynthesis, we develop a caprolactam-detecting genetic enzyme screening system (CL-GESS). The Alcaligenes 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 omega-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 omega-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.

A synthetic microbial biosensor for high-throughput screening of lactam biocatalysts.,Yeom SJ, Kim M, Kwon KK, Fu Y, Rha E, Park SH, Lee H, Kim H, Lee DH, Kim DM, Lee SG Nat Commun. 2018 Nov 29;9(1):5053. doi: 10.1038/s41467-018-07488-0. PMID:30498220^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.