| Literature DB >> 1138935 |
M Ehrlich, K Ehrlich, J A Mayo.
Abstract
Xanthomonas phage XP-12 contains 5-methylcytosine completely replacing cytosine. This substitution confers several unusual properties upon XP-12 DNA. The buoyant density of XP-12 DNA in CsCl gradients is 1.710 g/cm-3, 0.16 g/cm-3 lower than that expected for a normal DNA with the same percentage of adenine plus thymine. The melting temperature for XP-12 DNA in 0.012 M Na+ is the highest reported for any naturally occurring DNA, 83.2 degrees C, 6.1 degrees C higher than that of normal DNAs with the same percentage of adenine plus thymine. Unlike the minor amounts of 5-methylcytosine found in most plant and animal DNAs, the 5-methylcytosine residues of XP-12 derive their methyl group from the 3-carbon of serine instead of from the thiomethyl carbon of methionine. .Entities:
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Year: 1975 PMID： 1138935 DOI： 10.1016/0005-2787(75)90149-5
Source DB: PubMed Journal: Biochim Biophys Acta ISSN： 0006-3002