Localization of major group-specific polypeptides in the avian RNA tumor viruses

Abstract

Chloramine T iodination of intact avian myeloblastosis virus revealed, that the four major group-specific polypeptides were labeled unequally, with the largest polypeptide 4 (m.w. 23,000) being preferentially iodinated, when the labeling time was limited. By contrast, in enzymatic iodination of intact virus only major virion glycoprotein and glycolipids were extensively iodinated. These observations suggest that the protein 4 surrounds other group-specific polypeptides and is itself enveloped by the bilayer of glycolipids.