Arthrobacter luteus restriction endonuclease recognition sequence and its cleavage map of SV40 DNA

Physical mapping of human adenovirus type 7 DNA using a simple and sensitive method of terminal labeling

The tyrosine-containing peptide covalently attached to each 5'-terminus of adenovirus type 7 (Ad 7; Greider) DNA was labeled with 125I. The 5'-labeled DNA was subjected to digestion with several restriction endonucleases and the size of the labeled terminal fragments was determined. Partial hydrolysis by these endonucleases generated a series of labeled fragments which were fused to the terminal fragments and could, therefore, be detected by autoradiography. From the sizes of the partial products the location of the cleavage sites of the enzymes on Ad7 DNA could be determined. The subgenomic DNA extracted from incomplete particles by protease treatment could also be labeled with 125I, since it was found to contain the tyrosine-containing peptide covalently attached to the preferentially packaged left end of the genome.

BK virus DNA: complete nucleotide sequence of a human tumor virus

The complete DNA sequence of the human papovavirus BK is presented. From the 4963 base-pair sequence of BK virus (MM strain), the amino acid sequence of at least five proteins can be deduced: a T antigen and a t antigen, which share amino terminal peptides; proteins VP2 and VP3, which share 232 amino acids; and protein VP1, whose coding sequence overlaps those for VP2 and VP3 by 113 nucleotides but is read in a different frame. The gene loci and the arrangement of genes are strikingly similar in BK virus and simian virus 40 (SV40). The sequence of the deduced proteins in BK virus shares 73 percent amino acid homology with those in SV40, whereas the DNA sequence of the two viruses shares 70 percent homology, suggesting close evolutionary relationship. However, the repeated DNA sequences in the noncoding regions of these viruses are different.

The genome of simian virus 40

The nucleotide sequence of SV40 DNA was determined, and the sequence was correlated with known genes of the virus and with the structure of viral messenger RNA's. There is a limited overlap of the coding regions for structural proteins and a complex pattern of leader sequences at the 5' end of late messenger RNA. The sequence of the early region is consistent with recent proposals that the large early polypeptide of SV40 is encoded in noncontinguous segments of DNA.

The early region of SV40 DNA may have more than one gene

The nucleotide sequence of 70 base pairs (bp) around 0.545 map units (Alu I C and B junction) of the genome from the single Eco RI cleavage site within SV40 DNA is presented. The mRNA transcribed from the early strand template from this stretch contains two copies of the nonsense triplet UAA in each of the three reading frames. Thus at least 25% of the early region of SV40 DNA does not code for the SV40 "A" protein, and the viral contribution to events in the lytic cycle and transformation may be more complex than is generally appreciated.

A general method for inserting specific DNA sequences into cloning vehicles

A general method has been developed to introduce any double-stranded DNA molecule into cloning vehicles at different restriction endonuclease sites. In this method a chemically synthesized decadeoxyribonucleotide duplex, containing a specific restriction endonuclease sequence, is joinlex DNA is cut by the same restriction endonuclease to generate the cohesive ends. It is then inserted into the restriction endonuclease cleavage site of the cloning vehicle. To demonstrate the feasibility of this new method, we have inserted separately the synthetic lac operator DNA at the Bam I and HindIII cleavage sites of the plasmid pMB9 DNA.