Ambiguity of NRPS Structure Predictions: Four Bidentate Chelating Groups in the Siderophore Pacifibactin
Ambiguity of NRPS Structure Predictions: Four Bidentate Chelating Groups in the Siderophore Pacifibactin
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DOI：
10.1021/acs.jnatprod.8b01073
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发表时间：
2019-04-01
影响因子：
5.1
通讯作者：
Butler, Alison
中科院分区：
文献类型：
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作者：
Hardy, Clifford D.;Butler, Alison
通过生物信息学方法鉴定，太平洋桤木中的一个非核糖体肽合成酶基因簇编码新的铁载体pacificactin的生物合成。pacificactin的结构与生物信息学预测明显不同，包含四个双齿金属螯合位点，不典型的铁载体。本文报道了pacifiactin的基因组挖掘和结构表征，以及由于生物合成过程中缺乏腺苷酸化结构域保真度而可获得的pacifiactin变异的表征。用Fe（III）和Ga(III)- pacificactin络合物的C-13核磁共振光谱对pacificactin进行分光光度滴定，建立了1:1金属：pacificactin配位，并揭示了哪些双齿结合基团与金属配位。本文报道了铁（III）与β -羟基天冬氨酸配体配位引起的铁(III)- pacificactin光反应。
Identified through a bioinformatics approach, a nonribosomal peptide synthetase gene cluster in Alcanivorax pacificus encodes the biosynthesis of the new siderophore pacifibactin. The structure of pacifibactin differs markedly from the bioinformatic prediction and contains four bidentate metal chelation sites, atypical for siderophores. Genome mining and structural characterization of pacifibactin is reported herein, as well as characterization of pacifibactin variants accessible due to a lack of adenylation domain fidelity during biosynthesis. A spectrophotometric titration of pacifibactin with Fe(III) and C-13 NMR spectroscopy of the Ga(III)-pacifibactin complex establish 1:1 metal:pacifibactin coordination and reveal which of the bidentate binding groups are coordinated to the metal. The photoreaction of Fe(III)-pacifibactin, resulting from Fe(III) coordination of the beta-hydroxyaspartic acid ligands, is reported.