Isolation, characterization, cDNA cloning and gene expression of an avian transthyretin: Implications for the evolution of structure and function of transthyretin in vertebrates

Abstract

A chicken liver cDNA library was constructed in bacteriophage λgt10. A full‐length transthyretin cDNA clone was identified by screening with rat transthyretin cDNA and was sequenced. A three‐dimensional model of chicken transthyretin was obtained by computer‐graphics‐based prediction from the derived amino acid sequence for chicken transthyretin and from the structure of human transthyretin determined by X‐ray diffraction analysis [Blake, C. C. F., Geisow, M. J., Oatley, S. J., Rérat, B. & Rérat, C. (1978) J. Mol. Biol. 121, 339–356]. The similarity of the amino acid sequences of chicken and human transthyretins was 75% overall and 100% for the central channel containing the thyroxine‐bindin..