细菌中小分子冷休克蛋白的研究现状

Progress in bacterial small cold-shock proteins

小分子冷休克蛋白(cold shock protein,Csps)是微生物在适应低温生长条件下,细胞诱导合成的一系列分子量为7ku左右的蛋白质。它们绑定单链RNA和DNA并且在细胞数个生理过程中起着重要作用。冷休克蛋白首先在大肠杆菌中被发现,它与微生物对冷环境的适应及多种细胞功能有关。小分子冷休克蛋白一般由68到74个氨基酸构成,都存在5个反平行β折叠的β桶状片层结构。它们的主要功能是作为RNA分子伴侣(RNA chaperone)与mRNA结合,阻止mRNA二级结构形成,促进翻译。本文主要介绍了小分子冷休克蛋的结构、功能及其表达的调节机制。

Bacteria are able to adapt to temperatures far below their optimum growth temperatures, and a set of 7ku proteins （named cold shock proteins, CSPs） is strongly induced in response to a rapid decrease in growth temperature. CSPs preferentially bind single-stranded RNA and DNA and appear to play an important role in cell physiology. The cold shock proteins was first found in E. coil as DNA and RNA binding protein, and also responsible for the cell to adapt the low temperature. They are 65 - 70 amino acid residues long and all of the structures contain five antiparallel 13 strands that form a 13 barrel. CSPs may function as RNA chaperones, as they possess binding messenger RNA. In this way they could minimize the secondary folding of mRNA, thereby facilitating the translation process. We review about the structure, mechanism of regulation of the expression and possible functions of CSPs.