Nucleotide Sequence of the Simian Virus 40 HindII + III Restriction Fragment D and the Total Amino Acid Sequence of the Late Proteins VP2 and VP3

Abstract

Earlier papers from our laboratory reported the nucleotide sequence of the beginning of the simian virus 40 HindII + III fragment D (Hind-D, which contains the information for the presumed initiation codon for the VP2 protein), HindII + III fragment E (HindII + III fragment K (Hind-K, which contains the information for the termination signal for the VP2 and VP3 proteins and the initiation signal for the VP1 protein). We report here the nucleotide sequence of the remainder of fragment Hind-D as determined by the partial, chemical degradation procedure of Maxam and Gilbert [Proc. Natl Acad. Sci. U.S.A. (1977) 74, 560–564]. As the aforementioned restriction fragments cover the total of the overlapping VP2 and VP3 genes, the entire nucleotide sequence of these genes, as well as the derived amino acid sequence of the VP2 and VP3 proteins, is now known. Assuming that eukaryotic protein synthesis always starts with an AUG codon (and not with a GUG) and considering various evidence about the position of the VP3 gene within the VP2 gene, we conclude that the second AUG codon in phase coded by fragment Hind-D serves as the initiation codon for the translation of VP3. The first part of VP2 (98 residues), which is not present in VP3, is very hydrophobic and contains no cysteine or basic amino acids; possibly it serves for binding to, or penetrating through, membranes. The very basic carboxyl terminus of both VP2 and VP3 may possibly be involved in attachment to the DNA.