title: Characterization of a thioredoxin (BbTrx) from the entomopathogenic fungus Beauveria bassiana and its expression in response to thermal stress.
abstract: 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.
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
authors.forename: Sheng-Hua
authors.initials: SH
authors.lastname: Ying
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Wang
authors.forename: Ming-Guang
authors.initials: MG
authors.lastname: Feng
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D052982:Beauveria / Q000235:genetics*; D004926:Escherichia coli / Q000378:metabolism; D006358:Hot Temperature; D008969:Molecular Sequence Data; D013312:Stress, Physiological / Q000235:genetics / Q000502:physiology*; D013879:Thioredoxins / Q000235:genetics / Q000378:metabolism*
chemical_list: D013879:Thioredoxins