Graña Martin, Bellinzoni Marco, Miras Isabelle, Fiez-Vandal Cedric, Haouz Ahmed, Shepard William, Buschiazzo Alejandro, Alzari Pedro M
Institut Pasteur, Unité de Biochimie Structurale, URA CNRS 2185, 25 Rue du Dr Roux, 75724 Paris, France.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2009 Oct 1;65(Pt 10):972-7. doi: 10.1107/S1744309109035027. Epub 2009 Sep 18.
The gene Rv2714 from Mycobacterium tuberculosis, which codes for a hypothetical protein of unknown function, is a representative member of a gene family that is largely confined to the order Actinomycetales of Actinobacteria. Sequence analysis indicates the presence of two paralogous genes in most mycobacterial genomes and suggests that gene duplication was an ancient event in bacterial evolution. The crystal structure of Rv2714 has been determined at 2.6 A resolution, revealing a trimer in which the topology of the protomer core is similar to that observed in a functionally diverse set of enzymes, including purine nucleoside phosphorylases, some carboxypeptidases, bacterial peptidyl-tRNA hydrolases and even the plastidic form of an intron splicing factor. However, some structural elements, such as a beta-hairpin insertion involved in protein oligomerization and a C-terminal alpha-helical domain that serves as a lid to the putative substrate-binding (or ligand-binding) site, are only found in Rv2714 bacterial homologues and represent specific signatures of this protein family.
结核分枝杆菌的Rv2714基因编码一种功能未知的假定蛋白，它是一个基因家族的代表性成员，该家族主要局限于放线菌纲的放线菌目。序列分析表明，大多数分枝杆菌基因组中存在两个旁系同源基因，这表明基因复制是细菌进化中的一个古老事件。已确定Rv2714的晶体结构分辨率为2.6埃，揭示了一个三聚体，其中原体核心的拓扑结构与在一组功能多样的酶中观察到的相似，包括嘌呤核苷磷酸化酶、一些羧肽酶、细菌肽基 - tRNA水解酶，甚至是内含子剪接因子的质体形式。然而，一些结构元件，如参与蛋白质寡聚化的β - 发夹插入和作为假定底物结合（或配体结合）位点盖子的C末端α - 螺旋结构域，仅在Rv2714细菌同源物中发现，代表了该蛋白家族的特定特征。
