Frameshift mutations produced by proflavin in bacteriophage T4: specificity within a hotspot

摘要: Frameshift mutations were induced by proflavin in the rIIB gene of bacteriophage T4. DNA from each 48 independent frameshifts was inserted into M13mp8 and sequenced. Two-thirds (33/48) lie contiguous to one another 10 base pairs sequence. This hotspot differs markedly previously characterized mutagen-induced frameshift hotspots. Distinctive features include absence locally repetitive sequences, particularly G X C runs, fact that many different sequence changes are within at appreciable frequencies. Among 33 mutants hotspot, 8 distinguishable seen. All deletions a single or duplications more bases. Duplications frequent than deletions. The patterns suggest two specific phosphodiester bonds sites which proflavin-induced mutation is initiated.