title: Cytosine methylation as an effector of right-handed to left-handed DNA structural transitions.
abstract: Cytosine methylation has energetic and structural influences on left-handed Z-DNA formation in supercoiled plasmids. The restriction and modification enzymes from Haemophilus haemolyticus (HhaI and M.HhaI) provide a system to locate and analyze small segments of Z-DNA in large supercoiled plasmids. An approach is outlined that uses M.HhaI as an in vivo conformational probe for the detection of unusual DNA structures in a living cell. Also, characteristic features of the M.HhaI gene and protein are discussed.
authors.affiliation: Department of Biochemistry, School of Medicine, University of Alabama, Birmingham 35294.
authors.forename: W
authors.initials: W
authors.lastname: Zacharias
authors.forename: M
authors.initials: M
authors.lastname: Caserta
authors.forename: T R
authors.initials: TR
authors.lastname: O'Connor
authors.forename: J E
authors.initials: JE
authors.lastname: Larson
authors.forename: R D
authors.initials: RD
authors.lastname: Wells
mesh_terms: D044503:5-Methylcytosine; D001426:Bacterial Proteins / Q000378:metabolism; D003596:Cytosine / Q000031:analogs & derivatives* / Q000502:physiology; D004247:DNA / Q000032:analysis*; D004269:DNA, Bacterial / Q000648:ultrastructure; D004274:DNA, Recombinant / Q000648:ultrastructure; D004278:DNA, Superhelical / Q000648:ultrastructure*; D015257:DNA-Cytosine Methylases / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D008745:Methylation; D009690:Nucleic Acid Conformation; D010957:Plasmids
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004274:DNA, Recombinant; D004278:DNA, Superhelical; D044503:5-Methylcytosine; D003596:Cytosine; D004247:DNA; C037664:DNA modification methylase HhaI; D015257:DNA-Cytosine Methylases; D015252:Deoxyribonucleases, Type II Site-Specific; C037130:GCGC-specific type II deoxyribonucleases