【摘要】 酵母ＰＨＯ２蛋白及其变异体与ＰＨＯ５ＵＳＡ体外的相互作用杨军，敖世洲（中国科学院上海生物化学研究所分子生物学国家重点实验室，２０００３１）关键词酵母；ＰＨＯ２；突变；ＤＮＡ结合ＰＨＯ２是酵母阻遏型酸性磷酸酯酶基因转录的正调控因子［１］，由５５９个氨基...更多还原

【Abstract】 The GST gene fusion system was used to express PHO2 gene and its mutants in E. coli. Gel retardation assays showed that PHO2 fusion protein can bind to the upstream activation sequence (UAS) of the acid phosphatase gene PRO5. The homeodomain of PHO2 protein has such structure as α-helix 2-β-turn-α-helix 3,which acts as the DNA binding domain of the transcriptional factor. The Mutation of 11e 123 to Pro in helix 3 or the insertion of 4 amino acids (PDPD)between 112 and 113 in α-helix 2 led to the complete loss of DNA-binding activity of PHO2, while the mutation of Pro 117 to Ala in β-turn did not affect the binding activity significantly. Deletions of the PRO80 homologous region,acidic region or C-terminal 182 residues had no great effect on the DNA-binding activity, although these mutants had lost the ability to activate PHO5 expression in vivo.更多还原