Liu Tianzhe, Mazmouz Rabia, Neilan Brett A
School of Biotechnology and Biomolecular Sciences , The University of New South Wales , Sydney , NSW 2052 , Australia.
School of Environmental and Life Sciences , The University of Newcastle , Callaghan , NSW 2308 , Australia.
ACS Synth Biol. 2018 Apr 20;7(4):1143-1151. doi: 10.1021/acssynbio.8b00091. Epub 2018 Mar 27.
Phosphopantetheinyl transferases catalyze the post-translational modification of carrier proteins involved in both primary and secondary metabolism. The functional expression of polyketide synthases and nonribosomal peptide synthetases requires the activation of all carrier protein domains by phosphopantetheinyl transferases. Here we describe the characterization of five bacterial phosphopantetheinyl transferases by their substrate specificity and catalytic efficiency of four cyanobacterial carrier proteins. Comparative in vitro phosphopantetheinylation analysis showed Sfp possesses the highest catalytic efficiency over various carrier proteins. In vivo coexpression of phosphopantetheinyl transferases with carrier proteins revealed a broad range substrate specificity of phosphopantetheinyl transferases; all studied phosphopantetheinyl transferases were capable of converting apo- carrier proteins, sourced from diverse biosynthetic enzymes, to their active holo form. Phosphopantetheinyl transferase coexpression with the hybrid nonribosomal peptide synthetases/polyketide synthases responsible for microcystin biosynthesis confirmed that the higher in vitro activity of Sfp translated in vivo to a higher yield of production.
磷酸泛酰巯基乙胺基转移酶催化参与初级和次级代谢的载体蛋白的翻译后修饰。聚酮合酶和非核糖体肽合成酶的功能表达需要磷酸泛酰巯基乙胺基转移酶激活所有载体蛋白结构域。在此，我们通过四种蓝藻载体蛋白的底物特异性和催化效率描述了五种细菌磷酸泛酰巯基乙胺基转移酶的特性。比较体外磷酸泛酰巯基乙胺化分析表明，Sfp对各种载体蛋白具有最高的催化效率。磷酸泛酰巯基乙胺基转移酶与载体蛋白的体内共表达揭示了磷酸泛酰巯基乙胺基转移酶具有广泛的底物特异性；所有研究的磷酸泛酰巯基乙胺基转移酶都能够将来自不同生物合成酶的脱辅基载体蛋白转化为其活性全酶形式。磷酸泛酰巯基乙胺基转移酶与负责微囊藻毒素生物合成的杂合非核糖体肽合成酶/聚酮合酶的共表达证实，Sfp在体外的较高活性在体内转化为更高的产量。
