THE HUMAN α 1 -ANTITRYPSIN GENE: ITS SEQUENCE HOMOLOGY AND STRUCTURAL COMPARISON WITH THE CHICKEN OVALBUMIN GENE

ABSTRACT. α 1 -Antitrypsin deficiency is a genetic disorder that predisposes affected individuals to development of chronic obstructive pulmonary emphysema and/or infantile liver cirrhosis. The human chromosomal α1-antitrypsin gene has been cloned. Electronmicroscopic analysis and restriction mapping have indicated that this gene contains 3 intervening sequences in the peptide-coding region. DNA sequences coding for the amino and carboxyl-termini of α1-antitrypsin have been identified. Human α1-antitrypsin and chicken ovalbumin share significant sequence homology and belong to a common protein super-family. Yet the number, position and size of intervening sequences reveal that the two genes are dissimilar. The evolutionary origin of these two genes is discussed.