The structure of cruciforms in supercoiled DNA: probing the single‐stranded character of nucleotide bases with bisulphite

• Published in: The EMBO journal Vol. 5; no. 1; pp. 191 - 196
• Main Authors: Gough, G.W., Sullivan, K.M., Lilley, D.M.
• Format: Journal Article
• Language: English
• Published: England 01.01.1986
• Subjects: Base Sequence; Chloramphenicol - pharmacology; DNA Restriction Enzymes; DNA, Single-Stranded; DNA, Superhelical; Escherichia coli - drug effects; Escherichia coli - genetics; Plasmids; Sulfites

The single‐stranded character of cytosine bases in three cruciform structures has been assessed by an examination of reactivity towards sodium bisulphite. Unpaired cytosine residues undergo deamination at C4 to give deoxyuracil, and propagation in an ung Escherichia coli host results in C‐G‐‐‐‐T‐A t...