月季eIF－5A基因的表达增强宿主大肠杆菌对高温和低温的耐性

真核生物翻译起始因子（eIF－5A）是在调控生物生长发育、衰老与环境响应中起重要作用的蛋白质。设计eIF－5A基因的兼并引物，对月季受高温诱导的叶片cDNA进行PCR扩增，获得特异性片段回收、克隆和测序，确定该cDNA为月季eIF-5A(命名为RceIF5A)，含有480bp的核苷酸，编码159个氨基酸。将该cDNA序列克隆到原核表达载体PET32a中,获得重组子pET32a－eIF5A。高温（50℃）和低温（4℃）胁迫下含有该基因的大肠杆菌(Escherichia coli) BL21 (pET32a-eIF5A)比E. coli BL21 (pET32a)有明显的抗性提高，据此认为含有重组子的E. coli BL21 (pET32a-eIF5A)对高低温的抗性可能与eIF-5A基因的表达相关。该基因的GeneBank登录号为 EF177192。

Increasing the thermotolerance of E.coli with expression of eIF-5A from Rosa Chinenses.

Eukaryotic translation initiation factor 5A (elF5A ) is involved in celI proliferation, senescence, development and environmental response. cDNA of Chinese rose was amplified by PCR with degeneracy primer. The special fragment with 480 bp nucleic acid encoded a deduced amino acid sequence of 159 residues was obtained and named as RceIF-5A(GenBank No. EF177192). The gene was cloned into pET32a-vector and the recombination vector was named as pET32a-eIF5A. E.coli line BL21(pET32a-eIF5A) had more obvious tolerance than E. coli BL21 (pET32a) under the high(50℃) and low（4℃）temperature. By all accounts, thermotolerance enhancing was attributed to the heterogenous expression of eIF-5A gene in host cell line.