title: The SbcCD nuclease of Escherichia coli is a structural maintenance of chromosomes (SMC) family protein that cleaves hairpin DNA.
abstract: Hairpin structures can inhibit DNA replication and are intermediates in certain recombination reactions. We have shown that the purified SbcCD protein of Escherichia coli cleaves a DNA hairpin. This cleavage does not require the presence of a free (3' or 5') DNA end and generates products with 3'-hydroxyl and 5'-phosphate termini. Electron microscopy of SbcCD has revealed the "head-rod-tail" structure predicted for the SMC (structural maintenance of chromosomes) family of proteins, of which SbcC is a member. This work provides evidence consistent with the proposal that SbcCD cleaves hairpin structures that halt the progress of the replication fork, allowing homologous recombination to restore DNA replication.
authors.affiliation: Institute of Cell and Molecular Biology, University of Edinburgh, Kings Buildings, Edinburgh EH9 3JR, United Kingdom.
authors.forename: J C
authors.initials: JC
authors.lastname: Connelly
authors.forename: L A
authors.initials: LA
authors.lastname: Kirkham
authors.forename: D R
authors.initials: DR
authors.lastname: Leach
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D003851:Deoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D029968:Escherichia coli Proteins; D005092:Exonucleases / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D009687:Nuclear Proteins; C061563:SbcC protein, Bacteria; C489229:SbcC protein, E coli; D003851:Deoxyribonucleases; D005092:Exonucleases; C081229:sbcD protein, E coli