风筝蛋白：一类在细菌、古菌和真核生物中保守的SMC/kleisin伴侣超家族

Kite Proteins: a Superfamily of SMC/Kleisin Partners Conserved Across Bacteria, Archaea, and Eukaryotes.

作者信息

Palecek Jan J, Gruber Stephan

机构信息

Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic; Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic.

Max Planck Institute of Biochemistry, Chromosome Organization and Dynamics, Am Klopferspitz 18, 82152 Martinsried, Germany.

出版信息

Structure. 2015 Dec 1;23(12):2183-2190. doi: 10.1016/j.str.2015.10.004. Epub 2015 Nov 12.

DOI:10.1016/j.str.2015.10.004

PMID:26585514

Abstract

SMC/kleisin complexes form elongated annular structures, which are critical for chromosome segregation, genome maintenance, and the regulation of gene expression. We describe marked structural similarities between bacterial and eukaryotic SMC/kleisin partner proteins (designated here as "kite" proteins for kleisin interacting tandem winged-helix (WH) elements of SMC complexes). Kite proteins are integral parts of all prokaryotic SMC complexes and Smc5/6 but not cohesin and condensin. They are made up of tandem WH domains, form homo- or heterodimers via their amino-terminal WH domain, and they associate with the central part of a kleisin subunit. In placental mammals, the kite subunit NSE3 gave rise to several (>60) kite-related proteins, named MAGE, many of which encode tumor- and testis-specific antigens. Based on architectural rather than sequence similarity, we propose an adapted model for the evolution of the SMC protein complexes and discuss potential functional similarities between bacterial Smc/ScpAB and eukaryotic Smc5/6.

摘要

SMC/kleisin复合物形成细长的环状结构，这对于染色体分离、基因组维持和基因表达调控至关重要。我们描述了细菌和真核生物SMC/kleisin伴侣蛋白（在此处称为“风筝”蛋白，用于SMC复合物中与kleisin相互作用的串联翼状螺旋（WH）元件）之间显著的结构相似性。风筝蛋白是所有原核生物SMC复合物和Smc5/6的组成部分，但不是黏连蛋白和凝缩蛋白的组成部分。它们由串联的WH结构域组成，通过其氨基末端的WH结构域形成同二聚体或异二聚体，并与kleisin亚基的中央部分结合。在胎盘哺乳动物中，风筝亚基NSE3产生了几种（>60种）与风筝相关的蛋白，称为MAGE，其中许多编码肿瘤和睾丸特异性抗原。基于结构而非序列相似性，我们提出了一个适用于SMC蛋白复合物进化的模型，并讨论了细菌Smc/ScpAB和真核生物Smc5/6之间潜在的功能相似性。