Human adenovirus 2 temperature-sensitive mutant 112 contains three mutations in the protein IIIa gene

The temperature-sensitive (ts) mutant 112 of human adenovirus 2 is defective in the late stage of virus maturation. The region of functional mutation has been localised by marker rescue. It was observed that the ts mutation can be rescued by the left-hand part of the wild-type gene (nucleotides 12,301-12,891). By nucleotide sequencing, two mutations, both C to T (at position 12,386 and 12,741), were found in this region. The first one, in the glycine 20 codon, is silent, whereas the second changes alanine 145 to valine. A third mutation, which changed C to A (nucleotide 13,613), was identified in the right-hand part of the gene, resulting in the replacement of alanine-436 by threonine.