Molecular Cloning、sequence Characterization And Expressionpattern Of Rab18、BURP Domain-containing Protein17 Gene From Citrullus Lanatus

Separation and identification is the basis of study gene structure, reveal gene function and expression signal regulation, so that cloning of functional genes is a key point in fields of life science research.The complete m RNA sequence of the watermelon Rab18(Gen Bank Accession No.KM235552.1)and BURP domain-containing protein 17 gene(Gen Bank Accession No.KM235553.1)was amplified through rapid amplification of c DNA ends(RACE) method,And on this basis, according to the preliminary analysis of bioinformatics tools protein sequence characteristics of two genes, for subsequent research foundation of the function of two genes in watermelon, watermelon for cloning provides an effective way to functional genes.The main test methods and conclusions are as follows:1. According to the existing sequence in watermelon EST database, the full-length m RNA was separated Rab18 gene from watermelon1,010 bp containing a 645 bp open reading frame, which encodes a protein of 214 amino acids. The theoretical isoelectric point(p I) and molecular weight(Mw) of the deduced proteins of this watermelon gene were also computed by Protparam software. The p I of watermelon Rab18 is 5.97. The molecular weight of this putative protein is 23762.12. According to analyze by Ex PASY software,the result showed that Rab18 protein does not have hydrophobic area and a signal peptide of transmembrane proteins,the proportion of secondary structure of Rab18 protein are Alpha helix26.64%,β-Randomcoil33.64%,Bete-turn9.35%,30.37%Extended-strand30.37%.Seque nce analysis by Clustal W revealed that watermelon Rab18 protein shares high homology with the Rab18 of cucumber(99%), muskmelon(98%), morus notabilis(90%), tomato(89%), wine grape(89%) and potato(88%).Phylogenetic analysis revealed that watermelon Rab18 gene has a closer genetic relationship with the Rab18 gene of cucumber and muskmelon. Tissue expression profile analysis was carried out and results indicated that the watermelon Rab18 gene was highly expressed in root, stem and leaf, moderately expressed in flower, and weakly expressed in fruit.2. According to the existing sequence in watermelon EST database, the full-length m RNA was separated BURP domain-containing protein 17 gene from watermelon1,085 bp containing a 996 bp open reading frame, which encodes a protein of 331 amino acids. The theoretical isoelectric point(p I) and molecular weight(Mw) of the deduced proteins of this watermelon gene were also computed by Protparam software. The p I of watermelon BURP domain-containing protein 17 gene is 6.89. The molecular weight of this putative protein is 37446.12. According to analyze by Ex PASY software,the result showed that does have hydrophobic area and a signal peptide of transmembrane proteins,the proportion of secondary structure of BURP domain-containing protein 17 gene are 24.77%Alpha helix,Random coil19.94%,Bete-turn7.55%,Extended-strand47.73%. Sequence analysis revealed that watermelon BURP domain-containing protein 17 shares high homology with the BURP domain-containing protein 17 of cucumber(82%), muskmelon(82%), apple(58%), soybean(57%) and wine grape(54%). Results also showed that watermelon BURP domain-containing protein 17 gene has a closer genetic relationship with the BURP domain-containing protein 17 gene of cucumber and muskmelon. Tissue expression profile analysis was carried out and results revealed Tissue expression profile analysis was carried out and results revealed that the watermelon BURP domain-containing protein 17 gene was highly expressed in root and stem, moderately expressed in flower and leaf, and weakly expressed in fruit.