title: Cloning and sequencing of a sheep metallothionein cDNA.
abstract: A partially purified metallothionein mRNA fraction from copper-injected sheep liver was used to synthesize double-stranded cDNA, which was dC-tailed, annealed to dG-tailed pBR322 and used to transform Escherichia coli MC1061. Of the 1500 recombinant clones only one gave a positive signal when screened with a mouse metallothionein 1 probe. This clone (pSMT-1) contained an insert which included the entire coding region of a sheep metallothionein, the whole 3'-untranslated region, part of the poly(A)-tail and 25 bases of the 5'-untranslated region. DNA sequence analysis showed that this sheep metallothionein was very similar to other mammalian metallothioneins except for a threonine to proline change at amino acid 27. The clone also contained a different polyadenylation signal d(A-G-T-A-A-A) from that usually found d(A-A-T-A-A-A). Comparison of the DNA sequence of the sheep metallothionein with those of other species revealed an interesting region of homology close to the poly(A) addition signal in the 3'-untranslated region of the mRNA.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D055598:Chemical Phenomena; D002621:Chemistry; D003001:Cloning, Molecular; D003300:Copper / Q000494:pharmacology; D004247:DNA; D006801:Humans; D008099:Liver / Q000032:analysis; D008297:Male; D008668:Metallothionein / Q000235:genetics*; D051379:Mice; D009693:Nucleic Acid Hybridization; D011392:Proline / Q000302:isolation & purification; D012333:RNA, Messenger / Q000302:isolation & purification; D012756:Sheep; D013045:Species Specificity; D013912:Threonine / Q000302:isolation & purification
chemical_list: D012333:RNA, Messenger; D013912:Threonine; D003300:Copper; D004247:DNA; D008668:Metallothionein; D011392:Proline