Screening Transcription Factor Of Laccase Poxc In Pleurotus Ostreatus By Yeast One Hybrid System

In this study, we chose P. ostreatus new831as the research objectto screen transcription factors of poxc gene. The main research contents andconclusions are as follows:Based on the semi quantitative results of laccase gene poxc, after the analysis onPlantcare and Softberry, a part of the promoter was selected from laccase poxc gene toconstruct the bait vector; We got the bait strains by transforming bait plasmids intocompetent yeast cells; ds cDNA library was constructed by using high-quality RNAfrom young mushroom fruit; the library was transformed into competent cells ofbait strains, after the SD/-Leu/-Ura/AbA plate screening, finally， we got4genessequences, whose corresponding proteins could bind with the poxc gene promoter.the sequences were named as laccase transcription factor1（ltf1）\laccasetranscription factor2（ltf2）\laccase transcription factor3（ltf3）\laccase transcriptionfactor4（ltf4）, and submitted to the GeneBank, of which accession numbers wereKJ720282\KJ720283\KJ720284\KJ720285. After the prediction of the correspondingproteins sequences, their hydrophbicity\transmembrane domain\signal peptidesequences were analysed. At last, the2-dimensional structure was predicted bySPOMA software and3-dimensional structure by SWISS-MODEL web. According tothe analysis results, the homology between ltf1and aspartate aminotransferase was16%, at the same time, ltf1had the capacity of binding with pyridoxal phosphate, butit was not a transcription factor. Ltf2had homology with iron sulfurprotein transporter gene, multidrug resistance protein gene PGP1, MsbA protein geneABC transporter, the similar rates was about50%, it had an obvious oligomerzationsite, could regulate the genes through interactions between proteins. Ltf3had highhomology with bestrophin, as with ltf2, had an obvious oligomerzation site, couldregulate the genes through interactions between proteins. However, ltf4had highhomology with the HTH type transcription factor gabR, presumably as a transcription factor. At the same time, the open reading frame of ltf3was verified by prokaryoticexpression.