Phsical Map of Phage 2C DNA: Evidence for the Existence of Large Redundant Ends

• Published in: European journal of biochemistry Vol. 132; no. 1; pp. 69 - 75
• Main Authors: CONENE, Marc, HOET, Philippe, COCITO, Carlo
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-04-1983
• ISSN: 0014-2956; 1432-1033
• DOI: 10.1111/j.1432-1033.1983.tb07326.x

The chromosome o0f the Bacillus Subtilkis phage 2C, a linear nmolecule of duble‐stranded DNA of about 108 Da, in which thymine is completely replaced by hydroxymethluracil, was cleaved by different endonucleases. In some cases restriction segmentsd were much fewer than expectded, suggesting a possible interference oif the unusual base with the recognition mechanism of endonucleases. The physical map of 2C DNA was established by use fo SalI and HaeIII restriction endonucleases, which yielded a limited numbver of fragments. The expected number of fragments was 240 for HaeIII and 23 for SalI; in realitym, five segmenbts were obsereved up[on clevage with HaeIII and four with SalI. The terminal fragments of the genome were first identified; the other fragments were ordered by hybridizaiton and maoleculkar wight determination of restriction fragments showed the prewsence of homologous regfions at the ends of the 2C genome. The structure fo thses direct repretitive sequences was analyzed by clevage with HaeIII and hybridization with Eco RI restriction fragments. Their size (9.2 MDa) was found to be about 1/11 of that of the whole chromnosome.