Open AccessCloning and sequencing of a sheep metallothionein cDNA
Author(s) -
PETERSON M. Gregory,
LAZDINS Ieva,
DANKS David M.,
MERCER Julian F. B.
Publication year - 1984
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1984.tb08399.x
Subject(s) - metallothionein , complementary dna , polyadenylation , biology , microbiology and biotechnology , untranslated region , coding region , cloning (programming) , signal peptide , molecular cloning , clone (java method) , recombinant dna , dna , messenger rna , gene , genetics , computer science , programming language
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.