title: A stand-alone adenylation domain forms amide bonds in streptothricin biosynthesis.
abstract: The streptothricin (ST) antibiotics, produced by Streptomyces bacteria, contain L-β-lysine ((3S)-3,6-diaminohexanoic acid) oligopeptides as pendant chains. Here we describe three unusual nonribosomal peptide synthetases (NRPSs) involved in ST biosynthesis: ORF 5 (a stand-alone adenylation (A) domain), ORF 18 (containing thiolation (T) and condensation (C) domains) and ORF 19 (a stand-alone A domain). We demonstrate that ST biosynthesis begins with adenylation of L-β-lysine by ORF 5, followed by transfer to the T domain of ORF 18. In contrast, L-β-lysine molecules adenylated by ORF 19 are used to elongate an L-β-lysine peptide chain on ORF 18, a reaction unexpectedly catalyzed by ORF 19 itself. Finally, the C domain of ORF 18 catalyzes the condensation of L-β-lysine oligopeptides covalently bound to ORF 18 with a freely diffusible intermediate to release the ST products. These results highlight an unusual activity for an A domain and unique mechanisms of crosstalk within NRPS machinery.
authors: Department of Bioscience, Fukui Prefectural Universifty, Fukui, Japan.
authors: Chitose
authors: C
authors: Maruyama
authors: Junya
authors: J
authors: Toyoda
authors: Yasuo
authors: Y
authors: Kato
authors: Miho
authors: M
authors: Izumikawa
authors: Motoki
authors: M
authors: Takagi
authors: Kazuo
authors: K
authors: Shin-ya
authors: Hajime
authors: H
authors: Katano
authors: Takashi
authors: T
authors: Utagawa
authors: Yoshimitsu
authors: Y
authors: Hamano
mesh_terms: D000249:Adenosine Monophosphate / Q000378:metabolism*; D000577:Amides / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D005810:Multigene Family; D016366:Open Reading Frames; D021241:Spectrometry, Mass, Electrospray Ionization; D013309:Streptothricins / Q000096:biosynthesis*
chemical_list: D000577:Amides; D000249:Adenosine Monophosphate; D013309:Streptothricins