Adam Sebastian, Klein Andreas, Surup Frank, Koehnke Jesko
Structural Biology of Biosynthetic Enzymes, Helmholtz Institute for Pharmaceutical Research Saarland, Universität des Saarlandes Gebäude E8.1, 66123 Saarbrücken, Germany.
Microbial Drugs, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
Acta Crystallogr F Struct Biol Commun. 2019 Mar 1;75(Pt 3):205-211. doi: 10.1107/S2053230X19000712. Epub 2019 Feb 21.
Natural products often contain interesting new chemical entities that are introduced into the structure of a compound by the enzymatic machinery of the producing organism. The recently described crocagins are novel polycyclic peptides which belong to the class of ribosomally synthesized and post-translationally modified peptide natural products. They have been shown to bind to the conserved prokaryotic carbon-storage regulator A in vitro. In efforts to understand crocagin biosynthesis, the putative biosynthetic genes were expressed and purified. Here, the first crystal structure of a protein from the crocagin-biosynthetic gene cluster, CgnJ, a domain of unknown function protein, is reported. Possible functions of this protein were explored by structural and sequence homology analyses. Even though the sequence homology to proteins in the Protein Data Bank is low, the protein shows significant structural homology to a protein with known function within the competency system of Bacillus subtilis, ComJ, leading to the hypothesis of a similar role of the protein within the producing organism.
天然产物通常含有有趣的新化学实体，这些实体是由产生该化合物的生物体的酶机制引入到化合物结构中的。最近描述的番红花肽是新型多环肽，属于核糖体合成和翻译后修饰的肽类天然产物。已证明它们在体外能与保守的原核生物碳储存调节因子A结合。为了了解番红花肽的生物合成，对假定的生物合成基因进行了表达和纯化。在此，报道了来自番红花肽生物合成基因簇的一种蛋白质CgnJ的首个晶体结构，CgnJ是一种功能未知的结构域蛋白。通过结构和序列同源性分析探索了该蛋白的可能功能。尽管与蛋白质数据库中的蛋白质序列同源性较低，但该蛋白与枯草芽孢杆菌感受态系统中具有已知功能的一种蛋白质ComJ显示出显著的结构同源性，从而提出该蛋白在产生生物体中具有类似作用的假说。
