دانلود رایگان مقاله انگلیسی کلونینگ مولکولی Tyrosylprotein sulfotransferase حلزون دریایی - نشریه الزویر

Abstract

The gene of tyrosylprotein sulfotransferase, which was discovered in mammals, has been widely found in marine mollusk Littorina sitkana. High conservation of this gene indicates the functional importance of TPST in the metabolism of the living world. The cDNA encoding TPST in the mollusk was cloned and sequenced, and the enzyme was assigned on the basis of amino acid sequence similarity as tyrosylprotein sulfotransferase-2 (TPST-2). The putative homology model for the catalytic domain of TPST from L. sitkana was constructed according to crystal structure of the catalytic domain of the human TPST-2. The putative model of dimer structure showed that the active site involved two monomers and the dimer contains two active centers

Discussion

The primary structure of TPST from marine mollusk L. sitkana was determined by cDNA sequencing. The comparison of the LsTPST amino acid sequence with two human TPSTs and the TPSTs of other invertebrate species revealed 70–85% of structural homology. It should be noted that the maximal degree of homology was 85% with the protein from С. gigas (GenBank EKC35269). The degree of amino acid homology with TPSTs of vertebrates is also high: 74–81%. Analysis of the sequence of LsTPST using the InterProScan server indicates that it contains a catalytic domain of TPST-2 from Arg5 to Gly355. The multiple alignment of the amino acid sequences of TPST-1 (GenBank O60507) and TPST-2 (GenBank O60704) from human and some invertebrates — insects Drosophila melanogaster (GenBank AAM94031) and C. quinquefasciatus (GenBank EDS40555), clam C. gigas (GenBank EKC35269), nematodes C. elegans (GenBank O77081) and sea squirts H. roretzi (GenBank AAM09087) is presented in Fig. 4.