Nucleotide Sequence of the Simian Virus 40 Hin d‐K Restriction Fragment

The restriction fragment Hin d‐K represents 4.2% of the genome of Simian virus 40 (SV40) and is located near the middle of the late region. Its nucleotide sequence is reported here. It was mainly established by analysis of transcription products, synthesized by means of Escherichia coli RNA polymerase and nucleoside triphosphates, one of which was (α‐ 32 P)‐labeled. Strand assignment was possible by hybridization of asymmetric, labeled transcripts of total SV40 DNA to filter‐bound Hin d‐K fragment. Further information and unambiguous confirmation of the sequence was obtained by the use of direct DNA‐sequencing methods. For this purpose the fragment was labeled at the 5′ ends by means of polynucleotide kinase and [γ‐ 32 P]ATP and redigested with a suitable restriction enzyme. The separated products were then either partially degraded with snake venom diesterase for analysis by the ‘wandering spot' method or partially degraded with the base‐specific reagents dimethylsulphate or hydrazine for direct sequence analysis on gel. The Hin d‐K sequence is 219 base pairs long. The message strand is particularly rich in adenosine (39%) and purines. The nucleotide sequence can unambiguously be translated into an amino acid sequence and the N‐terminal codon of the viral protein VP1 gene could be identified. The amino‐terminal part of VP1 is rich in proline and lysine. The nucleotide sequence of Hin d‐K codes also for the carboxyl‐terminal part of the viral protein VP2 and VP3 genes, which partly overlap the VP1 gene.