title: Site of unequal sister chromatid exchange contains a potential Z-DNA-forming tract.
abstract: Previous studies from this laboratory have provided evidence that the duplication of the IgG2a heavy chain constant region gene (C gamma 2a) in the murine myeloma cell line MPC-11 occurred via unequal sister chromatid exchange. We now report the determination of the DNA sequences of the germ-line regions in which this exchange has occurred. The two donor sequences have long regions of virtual identity. Furthermore, both chromatids contain stretches of T-C and T-G dinucleotides; the latter has the potential to form Z-DNA. Localization of the actual breakpoints via genomic Southern blot analysis suggests a novel mechanism for the recombination and strongly implicates the simple sequence in the process.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D005796:Genes; D005803:Genes, Immunoglobulin; D007127:Immunoglobulin Constant Regions / Q000235:genetics; D007074:Immunoglobulin G / Q000235:genetics; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010954:Plasmacytoma; D012689:Sequence Homology, Nucleic Acid; D012854:Sister Chromatid Exchange
chemical_list: D007127:Immunoglobulin Constant Regions; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D004247:DNA