Demonstration of the production of frameshift and base-substitution mutations by quasipalindromic DNA sequences.
AUTOR(ES)
de Boer, J G
RESUMO
The in vivo production of frameshift and base-substitution mutations predicted as a consequence of the metabolic processing of misaligned quasipalindromic DNA sequences has been confirmed. Spontaneous frameshift mutations of the T4 rII gene that had been genetically mapped to quasipalindromic DNA sequences were sequenced. Some of the mutant sequences are exactly those predicted by a mutational model based on misaligned quasipalindromes. Furthermore, these sequences are distinct from those predicted by the classical frameshift model based on misaligned repeated sequences. The rII frameshift mutant sequences reported here result from the deletion of a specific base or bases that would remain looped out should the quasipalindromes assume a hairpin secondary structure. One hairpin predicted not only the deletion of two bases (a frameshift) but the concomitant production of nearby but noncontiguous base substitutions. The substitution of as many as three bases as well as the frameshift were predicted to arise as a consequence of a single mutational event in the palindrome. Two independent examples of the predicted deletion frameshift were found among the small sample of sequenced spontaneous frameshifts examined and both were associated with the predicted transversion and transition base substitutions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=391739Documentos Relacionados
- Specificity and efficiency of editing of mismatches involved in the formation of base-substitution mutations by the 3'----5' exonuclease activity of phage T4 DNA polymerase.
- Generation and functional analyses for base-substitution mutants of the adenovirus 2 major late promoter.
- Model for the participation of quasi-palindromic DNA sequences in frameshift mutation.
- Induction of frameshift and base pair substitution mutations by the major DNA adduct of the endogenous carcinogen malondialdehyde
- DNA Sequences of Frameshift and Other Mutations Induced by Icr-170 in Yeast