Clustered alpha-amanitin resistance mutations in mouse.
We report the identification of three new alpha-amanitin resistance mutations in the gene encoding the largest subunit of mouse RNA polymerase II (RPII215). These mutations are clustered in a region of the largest subunit that is important for transcription elongation. This same domain has been identified as the site of alpha-amanitin resistance mutations in both Drosophila and Caenarhabditis elegans. The sequences encompassing this cluster of mutations are highly conserved among RNA polymerase II genes from a number of species, including those that are naturally more resistant to alpha-amanitin suggesting that this region of the largest subunit is critical for a conserved catalytic function. The mutations reported here change leucine 745 to phenylalanine, arginine 749 to proline, or isoleucine 779 to phenylalanine. Together with the previously reported asparagine 792 to aspartate substitution these mutations define a potential alpha-amanitin binding pocket in a region of the mouse subunit that could be involved in translocation of polymerase during elongation.
Bartolomei
M S
MS
Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Corden
J L
JL
D016475:3T3 Cells; D000483:Alleles; D000546:Amanitins / Q000633:toxicity*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004351:Drug Resistance / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction; D012319:RNA Polymerase II / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D000546:Amanitins; D012319:RNA Polymerase II