紫色红曲霉磁受体IscA1的基因克隆及功能分析

Gene Cloning and Functional Analysis of Magnetic Receptor IscA1 of Monascus purpureus

为初步揭示磁受体IscA1在紫色红曲霉中的生物学功能,采用同源克隆方法,经PCR扩增和DNA测序,获得紫色红曲霉(Monascus purpureus SKY219)中IscA1的编码区序列。进一步的生物信息学分析发现,IscA1蛋白具有典型的Fe-S簇生物合成超家族和磁受体的保守结构域,含有60个可能的磷酸化修饰位点,为不稳定的亲水蛋白,主要定位于线粒体。其二、三级结构组成以无规则卷曲为主,其次是α-螺旋、β-转角。蛋白互作的分析结果发现,IscA1可以与Fe-S簇装配辅助蛋白IscA2及Grx5发生非特异性结合,IscA1和Grx可以被分子伴侣DnaJ蛋白激活,IscA1和不同蓝光受体蛋白之间存在较强的亲和力。表明IscA1在紫色红曲霉的Fe-S簇合成和磁感应中发挥重要作用。

In order to preliminarily reveal the biological function of magnetic receptor IscA1 in Monascus purpureus,after the PCR amplification and DNA sequencing,the coding region sequence of IscA1 in Monascus purpureus SKY219 was obtained by using homologous cloning method in this study.The bioinformatics analysis further revealed that IscA1 protein had a typical domain of Fe-S cluster biosynthesis superfamily and magnetic receptor.And the protein also contained 60 possible phosphorylation modification sites.It was an unstable hydrophilic protein and mainly locateed in mitochondria.The secondary and tertiary structures of IscA1 were composed mainly of irregular crimp,secondlyα-helices andβ-fold.Byanalyzing protein interaction,it turned out that the IscA1 could bind non-specifically to Fe-S cluster assembly co-proteins IscA2 and Grx5.The IscA1 and Grx could be activated by their molecular chaperone protein DnaJ.Moreover,there could be a strong affinity between IscA1 and different blue light receptor proteins.The results indicated that IscA1 played an important role in Fe-S cluster synthesis and magnetic induction of Monascus purpureus.The resultslay a foundation for fully revealing the mechanism of magnetic receptor IscA1 mediating magnetic induction of of Monascus purpureus.