title: Structure-based Mechanistic Insights into Terminal Amide Synthase in Nosiheptide-Represented Thiopeptides Biosynthesis.
abstract: Nosiheptide is a parent compound of thiopeptide family that exhibit potent activities against various bacterial pathogens. Its C-terminal amide formation is catalyzed by NosA, which is an unusual strategy for maturating certain thiopeptides by processing their precursor peptides featuring a serine extension. We here report the crystal structure of truncated NosA1-111 variant, revealing three key elements, including basic lysine 49 (K49), acidic glutamic acid 101 (E101) and flexible C-terminal loop NosA112-151, are crucial to the catalytic terminal amide formation in nosiheptide biosynthesis. The side-chain of residue K49 and the C-terminal loop fasten the substrate through hydrogen bonds and hydrophobic interactions. The side-chain of residue E101 enhances nucleophilic attack of H2O to the methyl imine intermediate, leading to Cα-N bond cleavage and nosiheptide maturation. The sequence alignment of NosA and its homologs NocA, PbtH, TpdK and BerI, and the enzymatic assay suggest that the mechanistic studies on NosA present an intriguing paradigm about how NosA family members function during thiopeptide biosynthesis.
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Heng
authors.initials: H
authors.lastname: Guo
authors.affiliation: Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.
authors.forename: Tianlong
authors.initials: T
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Li
authors.initials: L
authors.lastname: Han
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Naiyan
authors.initials: N
authors.lastname: Rong
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Wenxian
authors.initials: W
authors.lastname: Lan
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Chunxi
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Renxiao
authors.initials: R
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Bio-Organic and Natural Product Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Chunyang
authors.initials: C
authors.lastname: Cao
mesh_terms: D019732:Amide Synthases / Q000737:chemistry*; D018360:Crystallography, X-Ray; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D013844:Thiazoles / Q000737:chemistry
chemical_list: D013844:Thiazoles; D019732:Amide Synthases; C014134:nosiheptide