Assembly intermediates among adenovirus type 5 temperature-sensitive mutants

Abstract

Temperature-sensitive mutants from 3 different complementation groups, ts5, ts19 and ts58, accumulated assembly intermediates at the restrictive temperature. The polypeptide composition of these intermediates is similar to that of the wild type, including the precursor polypeptides pVI, pVII and pVIII. ts5 and ts19 also contained cleaved precursors, indicating assembly into defective virions. The increase of infectious virus after temperature shift-down of ts19 and ts58 was rapid when compared with that of ts24, which does not accumulate intermediates, suggesting that intermediates formed at nonpermissive temperature may be processed to mature virus. Shift-down experiments reveal that only a fraction of the intermediates are utilized for virus assembly and that degradation of intermediates occurs at the restrictive temperature.