A 19-kDa protein, present in low copy number in purified adenovirus type 2, has been characterized. Several criteria were used to establish that this protein is neither a degradation product of the known structural proteins of the virion nor a minor, unusually modified, form of protein VII. This 19-kDa protein, unlike other virion proteins, possesses alkali-resistant phosphoamino acids. Analysis by partial proteolysis indicated that it is related to a 23-kDa phosphoprotein present in H2ts-1 virions assembled in infected cells maintained at 39°C. Affinity labeling with [3H]diisopropyl fluorophosphate showed that the 19-kDa protein contains the active site for a serine protease. We, therefore, conclude that the 19-kDa protein is the active form of the adenovirus-encoded endopeptidase, defined by the H2ts-1 mutation, and is synthesized as a 23-kDa precursor that appears to mature by autocatalysis.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1987|
All Science Journal Classification (ASJC) codes