Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, WI 53211, USA.
Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131-0001, USA.
Acta Crystallogr F Struct Biol Commun. 2020 Aug 1;76(Pt 8):372-383. doi: 10.1107/S2053230X20009814. Epub 2020 Jul 29.
Proteins belonging to the NTF2-like superfamily are present in the biosynthetic pathways of numerous polyketide natural products, such as anthracyclins and benzoisochromanequinones. Some have been found to be bona fide polyketide cyclases, but many of them have roles that are currently unknown. Here, the X-ray crystal structures of three NTF2-like proteins of unknown function are reported: those of ActVI-ORFA from Streptomyces coelicolor A3(2) and its homologs Caci_6494, a protein from an uncharacterized biosynthetic cluster in Catenulispora acidiphila, and Aln2 from Streptomyces sp. CM020, a protein in the biosynthetic pathway of alnumycin. The presence of a solvent-accessible cavity and the conservation of the His/Asp dyad that is characteristic of many polyketide cyclases suggest a potential enzymatic role for these enzymes in polyketide biosynthesis.
属于 NTF2 样超家族的蛋白质存在于许多聚酮类天然产物的生物合成途径中，如蒽环类和苯并异色满醌。其中一些已被发现是真正的聚酮化合物环化酶，但其中许多的作用目前尚不清楚。本文报道了三个功能未知的 NTF2 样蛋白的 X 射线晶体结构：来自链霉菌 A3(2)的 ActVI-ORFA 及其同源物 Caci_6494，后者来自未鉴定生物合成簇的 Catenulispora acidiphila 中的一种蛋白质，以及来自链霉菌 sp. CM020 的 Aln2，它是 alnumycin 生物合成途径中的一种蛋白质。溶剂可及腔的存在以及许多聚酮化合物环化酶所特有的 His/Asp 二联体的保守性表明这些酶在聚酮化合物生物合成中可能具有潜在的酶学作用。
