Effects of variation of inverted-repeat sequences on reactions mediated by the transposase of Tn21.
The frequencies of one-ended transposition and normal transposition of derivatives of Tn21 that contain mutant inverted-repeat sequences (IRs) have been measured. In general, there was a linear relationship between the log of the frequency of one-ended transposition of a mutant IR and the log of the frequency of normal transposition of an element flanked by a wild-type IR at one end and by the mutant IR at the other. This implied that one-ended and normal transposition share the rate-limiting step that determines the frequency of transposition and that both IRs are involved in the rate-limiting step in normal transposition. Surprisingly, it was found that only the outer 18 base pairs of the IR of Tn21 engaged accurately in both one-ended and normal transposition, at about 1% of the frequency of the wild-type IR.
Martin
C
C
Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain.
Grinsted
J
J
de la Cruz
F
F
D001483:Base Sequence; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005798:Genes, Bacterial; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D009154:Mutation; D009713:Nucleotidyltransferases / Q000502:physiology*; D010957:Plasmids; D012091:Repetitive Sequences, Nucleic Acid; D019895:Transposases
D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D009713:Nucleotidyltransferases; D019895:Transposases