Fu Xinmiao, Jiao Wangwang, Chang Zengyi
State Key Laboratory of Protein Engineering and Plant Genetic Engineering, Peking University, Beijing, China.
J Mol Evol. 2006 Mar;62(3):257-66. doi: 10.1007/s00239-005-0076-5. Epub 2006 Feb 10.
Small heat shock proteins (sHSPs), as one subclass of molecular chaperones, are important for cells to protect proteins under stress conditions. Unlike the large HSPs (represented by Hsp60 and Hsp70), sHSPs are highly divergent in both primary sequences and oligomeric status, with their evolutionary relationships being unresolved. Here the phylogenetic analysis of a representative 51 sHSPs (covering the six subfamilies: bacterial class A, bacterial class B, archae, fungi, plant, and animal) reveals a close relationship between bacterial class A and animal sHSPs which form an outgroup. Accumulating data indicate that the oligomers from bacterial class A and animal sHSPs appear to exhibit polydispersity, while those from the rest exhibit monodispersity. Together, the close evolutionary relationship and the similarity in oligomeric polydispersity between bacterial class A and animal sHSPs not only suggest a potential evolutionary origin of the latter from the former, but also imply that their oligomeric polydispersity is somehow a property determined by their primary sequences.
小热休克蛋白（sHSPs）作为分子伴侣的一个亚类，对于细胞在应激条件下保护蛋白质非常重要。与大型热休克蛋白（以Hsp60和Hsp70为代表）不同，sHSPs在一级序列和寡聚状态上都高度多样化，其进化关系尚未明确。在这里，对51种代表性sHSPs（涵盖六个亚家族：细菌A类、细菌B类、古菌、真菌、植物和动物）的系统发育分析揭示了细菌A类和动物sHSPs之间的密切关系，它们形成了一个外类群。越来越多的数据表明，细菌A类和动物sHSPs的寡聚体似乎表现出多分散性，而其余的则表现出单分散性。总之，细菌A类和动物sHSPs之间密切的进化关系以及寡聚多分散性的相似性不仅表明后者可能起源于前者，还暗示它们的寡聚多分散性在某种程度上是由其一级序列决定的特性。
