玉米SUT基因家族生物信息学分析

Bioinformatics Analysis of SUT Gene Family in Maize

蔗糖转运蛋白(SUCs或SUTs)是植物特有的一类跨膜转运蛋白,负责蔗糖的跨膜运输,在韧皮部蔗糖装载、卸载及长距离运输中发挥重要作用。为了挖掘植物SUT基因的功能,本研究对玉米SUT基因家族成员进行了系统的生物信息学分析。基于玉米基因组数据库,本研究鉴定到8个SUT基因,氨基酸大小在501~592之间,含有5~14个外显子,分布在1、3、4、5和9号染色体上。除ZmSUT2外,其他家族成员均为碱性蛋白质;只有ZmSUT3是不稳定蛋白,其余皆为稳定蛋白;所有ZmSUTs均为疏水性蛋白,主要定位在质膜上,无信号肽。ZmSUTs具有12个跨膜拓扑结构,属于易化扩散载体(MFS)家族和蔗糖/H^(+)共转运体(GPH)超家族成员,具有高度保守性。磷酸化位点预测结果显示,该家族具有多个潜在磷酸位点。蛋白二级结构具有相似的特征,α-螺旋和无规则卷曲为ZmSUTs的主要结构元件。系统进化分析显示ZmSUTs可分为4个亚家族(SUT2~SUT5),玉米与高粱SUTs亲缘关系最近,其次是水稻,最远是拟南芥。本研究通过玉米基因组分析,挖掘到8个SUT基因家族成员,系统分析其序列特征、蛋白理化性质、蛋白结构、进化关系等,为深入研究玉米SUT基因功能提供了参考依据。

Sucrose transporters(SUCs or SUTs),a kind of plant-specific trans-membrane transporters,are responsible for trans-membrane transport of sucrose and play an important role in loading and unloading of phloem.In order to explore the function of SUT gene in plants,this study conducted systematic bioinformatics methods of the SUT gene family in maize.Based on maize genome database,8 SUT genes were identified in this study.Amino acid length ranged from 501 aa to 592 aa,contained five to fourteen exons,and was unevenly located on chromosome 1,3,4,5 and 9.Except ZmSUT2,the other members were all alkaline proteins.Only ZmSUT3 displayed unstable protein,the other members all showed stable proteins.The ZmSUT family members were hydrophobic proteins,and almost located in plasma membrane without signal peptide.The ZmSUTs protein had 12 trans-membrane topology belonging to the major facilitator superfamily(MFS)and the sucrose/H^(+)symporter(glycoside-pentoside hexuronide,GPH)family.The prediction of phosphorylation sites showed that the family had many potential sites.The protein secondary structure revealed the similar characteristics,and the main secondary structural elements were alpha-helix and random coils.The Phylogenetic analysis indicated that SUT genes in maize could be divided into four subfamilies(SUT2~SUT5).The ZmSUT family members were closest to the Sorghum SUT family members,followed by rice,and the farthest to Arabidopsis thaliana.The research identified 8 SUT genes family from maize genome database and revealed the sequence feature,physicochemical propertry,protein structure,evolutionary relationship.These results will provide a reference for further study of SUT gene function in maize.