副猪嗜血杆菌肽聚糖相关脂蛋白(PalA)的序列分析及三维结构建模  

Sequence Analysis and Homology Modelling on Peptidoglycan-associated Lipoprotein A of Haemophilus parasuis

作　　者：周伦江[1] 车勇良[1] 陈如敬[1] 江斌[1] 王隆柏[1] 魏宏[1] 吴学敏[1] 庄向生[1] 

机构地区：[1]福建省农业科学院畜牧兽医研究所,福州350013

出　　处：《畜牧兽医学报》2012年第3期438-445,共8页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：福建省公益类科研专项(2010R1025-2);国家公益性行业(农业)科研专项(NYHYZX07-034)

摘　　要：为深入研究副猪嗜血杆菌(Haemophilus parasuis,Hps)肽聚糖相关脂蛋白(Peptidoglycan-associated lipo-protein,palA)的生物学特性,设计了一对特异性引物,应用PCR方法来扩增Hps palA的全基因序列,进行克隆和测序。采用生物信息学方法,对Hps的palA基因核苷酸及其编码氨基酸序列进行比对,选取其中的血清学5型分离株,对其PalA蛋白的分子结构、理化性质及结构功能域、蛋白质二级结构等重要参数进行了预测和分析,并对PalA蛋白的三级结构进行了同源建模。结果显示,PCR扩增出462bp的目的片段;测序结果显示出不同血清型Hps之间palA基因核苷酸序列相似性有一定的差异,而所对应的氨基酸序列却差异很小;密码子偏爱性分析表明palA基因主要偏好GCA和AAA;PalA蛋白的理论等电点为6.28,偏弱酸性;PalA蛋白的二级结构以α螺旋、不规则卷曲和延伸链为主要构件;Hps的PalA蛋白的氨基酸序列与流感嗜血杆菌Pal蛋白的相似性为71.97%,以Pal蛋白结构为模板成功构建了Hps的PalA蛋白三维结构分子模型,该PalA蛋白三维结构与Pal蛋白相似,也含有肽聚糖结合口袋区,主要由第80位的酪氨酸(Tyr)、第39位的苯丙氨酸(Phe)和第84位的亮氨酸(Leu)组成。Hps的PalA蛋白的成功建模为PalA蛋白功能的深入研究提供了参考依据。To lucubrate bionomics of PalA in Haemophilus parasuis （Hps）, the complete palA gene was amplified by PCR with a pair of specific primers designed and synthesized, and was cloned and sequenced. The Hps PalA was analyzed and predicted by the tools of bioinformatics in the following aspects： the composition and alignment of nucleic acid sequences and amino acid se- quences, molecular structure, physical and chemical characters, secondary and tertiary structure of protein and so on. The results revealed that 462 bp fragment of the palA gene was amplified by PCR; There were less similarity in nucleic acid sequences than amino acid sequences among five Hps strains; The palA gene preferred mostly to GCA and AAA; The PalA（PI= 6. 28） showed weak acidity; and main component of all secondary structures included a spiral, random coil and extended strand; The homology of the amino acid of Hps PalA and Haernophilus influ- enza Pal is 71.97% ; The 3D models of Hps PalA were successfully constructed based on the tern-plate of Pal of H. influenza; Like Pal, the tertiary structure of Hps PalA also contained a Bind- ing pocket region which included Y80, F39 and L84. The homology modelling successfully of Hps PalA provided a refer to lucubrate the PalA.

关 键 词：副猪嗜血杆菌 肽聚糖相关脂蛋白 序列分析 同源建模 

分 类 号：S852.612[农业科学—基础兽医学]