title: Structural, functional, and evolutionary relationships between lambda-exonuclease and the type II restriction endonucleases.
abstract: lambda-exonuclease participates in DNA recombination and repair. It binds a free end of double-stranded DNA and degrades one strand in the 5' to 3' direction. The primary sequence does not appear to be related to any other protein, but the crystal structure shows part of lambda-exonuclease to be similar to the type II restriction endonucleases PvuII and EcoRV. There is also a weaker correspondence with EcoRI, BamHI, and Cfr10I. The structure comparisons not only suggest that these enzymes all share a similar catalytic mechanism and a common structural ancestor but also provide strong evidence that the toroidal structure of lambda-exonuclease encircles its DNA substrate during hydrolysis.
authors.affiliation: Institute of Molecular Biology, Howard Hughes Medical Institute and Department of Physics, University of Oregon, Eugene, OR 97403, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Kovall
authors.forename: B W
authors.initials: BW
authors.lastname: Matthews
mesh_terms: D000818:Animals; D001665:Binding Sites; D004260:DNA Repair; D015245:Deoxyribonuclease BamHI / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015246:Deoxyribonuclease EcoRI / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D005090:Exodeoxyribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D011995:Recombination, Genetic; D013379:Substrate Specificity; D014764:Viral Proteins
chemical_list: D014764:Viral Proteins; D005090:Exodeoxyribonucleases; C043586:exo protein, Bacteriophage lambda; D015245:Deoxyribonuclease BamHI; D015246:Deoxyribonuclease EcoRI; C066244:endodeoxyribonuclease Cfr10I; C025630:CAGCTG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific; C027440:GATATC-specific type II deoxyribonucleases