title: Distinct DNA sequence and structure requirements for the two steps of V(D)J recombination signal cleavage.
abstract: Cleavage of V(D)J recombination signals by purified RAG1 and RAG2 proteins permits the dissection of DNA structure and sequence requirements. The two recognition elements of a signal (nonamer and heptamer) are used differently, and their cooperation depends on correct helical phasing. The nonamer is most important for initial binding, while efficient nicking and hairpin formation require the heptamer sequence. Both nicking and hairpin formation are remarkably tolerant of variations in DNA structure. Certain flanking sequences inhibit hairpin formation, but this can be bypassed by base unpairing, and even a completely single-stranded signal sequence is well utilized. We suggest that DNA unpairing around the signal-coding border is essential for the initiation of V(D)J combination.
authors.affiliation: Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0540, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Ramsden
authors.forename: J F
authors.initials: JF
authors.lastname: McBlane
authors.forename: D C
authors.initials: DC
authors.lastname: van Gent
authors.forename: M
authors.initials: M
authors.lastname: Gellert
mesh_terms: D001483:Base Sequence; D001704:Biopolymers; D004247:DNA / Q000235:genetics*; D004268:DNA-Binding Proteins; D005803:Genes, Immunoglobulin; D018398:Homeodomain Proteins; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011506:Proteins / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D011995:Recombination, Genetic; D015398:Signal Transduction
chemical_list: D001704:Biopolymers; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D011506:Proteins; D011948:Receptors, Antigen, T-Cell; C064655:V(D)J recombination activating protein 2; C064658:RAG-1 protein; D004247:DNA