Mapping the DNA fragments produced by cleavage by lambda DNA with endonuclease RI
Allet, B.; Jeppesen, P.G.; Katagiri, K.J.; Delius, H.
Nature 241(5385): 120-123
1973
ISSN/ISBN: 0028-0836 PMID: 4572006 Document Number: 64147
The analysis of in vitro DNA-directed transcription and coupled transcription/translation is usually complicated by the very large number of products that are made from each Dna molecule. If smaller Dna molecules could be used, the analysis would be correspondingly easier. The discovery of several restriction endonucleases, each recognizing a small number of unique cleavage sites per Dna molecule, could lead to a much deeper analysis of the complex structure and function of Dna by making it possible to isolate homogeneous Dna segments of manageable size. One of these enzymes, the Rtf Ri endonuclease, has recently been characterized by Yoshimuri, who has shown that it introduces a limited number of cuts in λ DNA1; by sucrose gradient sedimentation Yoshimuri separated a faster-moving peak containing one unique Dna population of molecular weight 13 × 106 from a slower-moving peak consisting of smaller fragments of average molecular weight 3.8 × 106. We describe here the further resolution of the products arising from digestion of linear λ Dna with the Ri endonuclease into six discrete fragments, and their subsequent characterization and mapping along the λ genome.