GENOMIC STRUCTURE OF RAT-LIVER ARYL SULFOTRANSFERASE IV-ENCODING GENE

This report contains the first description of the genomic structure fo r a sulfotransferase (ST). The gene (ASTIV) encodes rat hepatic aryl S T IV, also known as tyrosine-ester ST (EC 2.8.2.9). A phage genomic cl one containing 70% of the 3' AST gene coding sequence was isolated aft er screening a rat genomic library with an ASTIV cDNA. The remaining 5 ' sequence was determined from a PCR product obtained from rat genomic DNA and ASTIV cDNA-specific primers. ASTIV spans 3.5 kb and contains eight exons and seven introns. The fourth intron of this gene contains sequences homologous to rodent B1 repetitive elements and an Alu repe at found in rat. An alignment of the primary structures of ten differe nt ST revealed several conserved regions, as well as a putative bindin g site for the cofactor for enzymatic sulfation reactions, 3'-phosphoa denosine-5'-phosphosulfate.