title: Structure-Activity Analysis of Gram-positive Bacterium-producing Lasso Peptides with Anti-mycobacterial Activity.
abstract: Lariatin A, an 18-residue lasso peptide encoded by the five-gene cluster larABCDE, displays potent and selective anti-mycobacterial activity. The structural feature is an N-terminal macrolactam ring, through which the C-terminal passed to form the rigid lariat-protoknot structure. In the present study, we established a convergent expression system by the strategy in which larA mutant gene-carrying plasmids were transformed into larA-deficient Rhodococcus jostii, and generated 36 lariatin variants of the precursor protein LarA to investigate the biosynthesis and the structure-activity relationships. The mutational analysis revealed that four amino acid residues (Gly1, Arg7, Glu8, and Trp9) in lariatin A are essential for the maturation and production in the biosynthetic machinery. Furthermore, the study on structure-activity relationships demonstrated that Tyr6, Gly11, and Asn14 are responsible for the anti-mycobacterial activity, and the residues at positions 15, 16 and 18 in lariatin A are critical for enhancing the activity. This study will not only provide a useful platform for genetically engineering Gram-positive bacterium-producing lasso peptides, but also an important foundation to rationally design more promising drug candidates for combatting tuberculosis.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Inokoshi
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Koyama
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
authors.forename: Midori
authors.initials: M
authors.lastname: Miyake
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Shimizu
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tomoda
mesh_terms: D019943:Amino Acid Substitution; D000890:Anti-Infective Agents / Q000737:chemistry / Q000633:toxicity; D010456:Peptides, Cyclic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity; D012240:Rhodococcus / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D000890:Anti-Infective Agents; D010456:Peptides, Cyclic; C522551:lariatin A