signature=1cd92faae63d7f057ecdb0e66c7c6694,Functional characterization of host toxic EcdB transcript...

摘要：

The ecdB is a transcription factor, located in the echinocandin B biosynthetic gene cluster of Emericella rugulosa NRRL11440. Here, we validated the ecdB mRNA sequence for functional expression and to explore role of EcdB protein in the echinocandin B regulation. The sequence alignment study revealed that the ecdB coding sequence was found 75 bp shorter than the reference mRNA sequence. This coding sequence encodes for EcdB protein, comprised of three conserved domains; DNA binding domain, coiledヽoil domain, and signature middle homology region. The full﹍ength and DNA binding domain (truncated) DNA sequences were expressed in E. coli BL21(DE3) under different tested conditions. The expression of EcdB protein was found to be toxic which curbs the cell growth. In contrast to truncated protein (GST:EcdB1), the full﹍ength (GST:EcdB) protein was expressed at very low titer and not detectable in SDS㏄AGE under the varying IPTG, temperature, and media conditions. However, GST:EcdB1 was successfully purified under standard conditions (0.5mM IPTG at 0.5OD) with 33 kDa expected size. The functionality of GST:EcdB1 was attained by EMSA study as a clear band shifting showed with ecdA promoter. Taken together, we conclude that EcdB interacts with the ecdA promoter which reflected to require for echinocandin B regulation.

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