无蹼壁虎EMC3基因cDNA全长克隆与进化分析  

Full-length cloning and evolutionary analysis of the cDNA of EMC3 gene in Gekko swinhonis

作　　者：夏龙杰 吴海霞 时昕晔 严洁[1] 李鹏[1] XIA Longjie;WU Haixia;SHI Xinye;YAN Jie;LI Peng(College of Life Sciences,Nanjing Normal University,Nanjing 210023,China;College of Ocean Science and Engineering,Nanjing Normal University,Nanjing 210023,China)

机构地区：[1]南京师范大学生命科学学院,南京210023 [2]南京师范大学海洋科学与工程学院,南京210023

出　　处：《天津师范大学学报（自然科学版）》2023年第3期26-34,共9页Journal of Tianjin Normal University：Natural Science Edition

基　　金：国家自然科学基金资助项目(31000954);江苏省高等学校自然科学研究重大项目(19KJA330001);江苏省研究生科研与实践创新计划项目(KYCX20_1241)。

摘　　要：为了探究无蹼壁虎(Gekko swinhonis)EMC3基因(命名为GsEMC3)的序列特征,了解GsEMC3蛋白的结构和功能,探讨GsEMC3蛋白与其他物种EMC3蛋白的进化关系,采用SMART RACE技术克隆获得了GsEMC3的全长cDNA序列,通过信息学分析阐明了GsEMC3基因的序列特征以及GsEMC3蛋白的结构和功能,系统发育和选择压力分析研究了GsEMC3的进化特征.GsEMC3基因的cDNA全长为1023 bp,包含1个786 bp的开放阅读框,基因编码1个含261个氨基酸的多肽.GsEMC3蛋白的相对分子质量约为30.074×10^(3),理论等电点为5.57.生物信息学分析表明,无蹼壁虎GsEMC3为疏水性非分泌型蛋白,有2个跨膜区,可能是一个动态定位的蛋白,无信号肽,直接在细胞内发挥作用.其分子量与已知的其他物种的EMC3蛋白相近.GsEMC3蛋白含有1个DUF106结构域,二级结构包含12个α-螺旋、1个β-折叠、13个无规则卷曲.系统发育分析表明,无蹼壁虎GsEMC3蛋白序列与美国短吻鳄(Alligator mississippiensis)、安乐蜥(Anolis carolinensis)、绿海龟(Chelonia mydas)、科莫多巨蜥(Varanus komodoensis)等爬行动物的EMC3蛋白序列高度同源.选择压力分析表明,无蹼壁虎的GsEMC3蛋白受到纯化选择,其功能可能高度保守.To investigate the sequence characteristics of the EMC3 gene(named GsEMC3)of Gekko swinhonis,understand the structural features and functions of GsEMC3,and explore the evolutionary relationships between GsEMC3 and EMC3 pro-teins of other species,the full-length cDNA sequence of GsEMC3 was obtained by SMART RACE technique.The sequence characteristics of the GsEMC3 and the structural features and functions of GsEMC3 were elucidated by informatics analysis,and the evolutionary features of GsEMC3 were studied by phylogenetic analysis and selection pressure analysis.The full-length cDNA of GsEMC3 is 1023 bp and contains an open reading frame of 786 bp,which encodes a polypeptide containing 261 amino acids.The relative molecular mass of the GsEMC3 protein is about 30.074×10^(3),and the theoretical isoelectric point is 5.57.Bioinformatics analysis indicated that the GsEMC3 is a hydrophilic non-secretory protein with two transmembrane regions,which may be a dynamic localized protein without signal peptide,and its relative molecular mass is similar to that of known EMC3 proteins in other species.The GsEMC3 protein has only one DUF106 domain of unknown function,and the secondary structure consists of 12 alpha-helices,1 beta-sheets and 13 random coils.Phylogenetic analysis showed that the GsEMC3 protein sequence of G.swinhonis was highly homologous to that of Alligator mississippiensis,Anolis carolinensis,Chelonia mydas,Varanus komodoensis and other reptiles.Selection pressure analysis indicated that the GsEMC3 protein was subject to purifying selection and its function may be highly conserved.

关 键 词：无蹼壁虎 GsEMC3基因 CDNA 序列分析 选择压力 

分 类 号：Q71[生物学—分子生物学]