title: The cleavage of single-stranded DNA by the isoschizomeric restriction endonuclease HhaI and CfoI.
abstract: The cleavage of single-stranded (ss) M13mp8(+) DNA by the isoschizomeric restriction endonucleases HhaI and CfoI has been investigated. The two enzymes differ considerably in their ability to cleave ssDNA. HhaI cleaves ssDNA about two orders of magnitude faster than does CfoI, although both enzymes show the same activity when assayed on double-stranded DNA. From the cleavage of oligonucleotides and of M13mp8(+) DNA fragments it is concluded that cleavage of ssDNA occurs via transiently formed double-stranded hairpin structures. A rough correlation exists between the stability of the secondary structures and the cleavage efficiency.
mesh_terms: D003090:Coliphages / Q000235:genetics*; D004247:DNA / Q000378:metabolism; D004262:DNA Restriction Enzymes / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific; D007700:Kinetics; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D004277:DNA, Single-Stranded; D004279:DNA, Viral; D009838:Oligodeoxyribonucleotides; D004247:DNA; D004262:DNA Restriction Enzymes; D015252:Deoxyribonucleases, Type II Site-Specific; C037130:GCGC-specific type II deoxyribonucleases