The sequence of 967 amino acids at the carboxyl‐end of rat thyroglobulin: Location and surroundings of two thyroxine‐forming sites

The entire rat thyroglobulin mRNA sequence (about 8500 nucleotides) has been cloned in five recombinant plasmids containing overlapping cDNA inserts. The 3′ end of the mRNA is precisely defined by the poly (A) tail found in the furthest 3′ end clone. Evidence that most of the 5′ end is cloned come from size considerations and from a primer extension experiment. At the 3′ end of the mRNA only one long open reading frame is present in the sequence of 3018 nucleotides that has been established. In the deduced protein sequence we have localized two thyroxine‐forming sites in a region containing a high concentration of tyrosine residues.