[Specific splitting of the alpha-A-globin gene by molecular forms of DNA-topoisomerase type I from calf thymus].

The specificity of splitting of the cloned alpha A-globin gene from chicken erythrocytes induced by three topoisomerases I differing in molecular masses was demonstrated. The localization and relative number of topoisomerase breaks in the alpha A-globin gene vary in different topoisomerase I forms.