Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
Can J Microbiol. 2010 Nov;56(11):934-42. doi: 10.1139/w10-081.
A thioredoxin (BbTrx) was identified from the entomopathogenic fungus Beauveria bassiana. The cloned nucleotide sequence consisted of a 423-bp open reading frame encoding a 141-amino-acid thioredoxin, a 1011-bp 5' region, and a 419-bp 3' region. The deduced protein sequence of BbTrx, including a common 95-amino-acid conserved domain and a unique 46-amino-acid carboxy terminal region, was similar (≤38% identity) to that of other thioredoxins and phylogenetically closest to that from Neurospora crassa. In insulin solution containing dithiothreitol at 25 °C, recombinant BbTrx or a truncated form lacking the carboxy terminal region (BbTrxD) exhibited disulfide reduction activity. BbTrxD was more active after pre-incubation at 40-75 °C, and cells expressing BbTrxD showed significantly higher tolerance to thermal stress (51 °C). The BbTrx expression in B. bassiana was greatly elevated when stressed at 40 °C. The results indicate that the new thioredoxin is a potential target for improving the thermotolerance of B. bassiana formulations.
从昆虫病原真菌白僵菌中鉴定出一种硫氧还蛋白（BbTrx）。克隆的核苷酸序列由一个 423bp 的开放阅读框编码，编码一个 141 个氨基酸的硫氧还蛋白，一个 1011bp 的 5'区和一个 419bp 的 3'区。BbTrx 的推导蛋白序列，包括一个常见的 95 个氨基酸保守结构域和一个独特的 46 个氨基酸羧基末端区域，与其他硫氧还蛋白相似（≤38%的同一性），并且与粗糙脉孢菌的亲缘关系最近。在含有二硫苏糖醇的胰岛素溶液中，重组 BbTrx 或缺乏羧基末端区域的截断形式（BbTrxD）在 25°C 时表现出二硫键还原活性。BbTrxD 在 40-75°C 预孵育后更活跃，表达 BbTrxD 的细胞对热应激（51°C）表现出显著更高的耐受性。当在 40°C 下受到胁迫时，白僵菌中的 BbTrx 表达大大增加。结果表明，这种新的硫氧还蛋白是提高白僵菌制剂耐热性的潜在目标。
