title: The nucleotide sequences recognized by endonucleases AvaI and AvaII from Anabaena variabilis.
abstract: Determination of the 5'-terminal sequences flanking all the individual cleavage sites for endonuclease AvaI in bacteriophage-lambda DNA has shown that this enzyme recognizes the hexanucleotide sequences: (Formula: see text), This sequence is cut as shown by the arrows to give single-stranded 5'-tetranucleotide protrusions (cohesive ends). Endonucleases SmaI, XhoI and XmaI recognize different symmetrical subsets of this sequence and provide independent evidence for the occurrence of these subsets at particular endonuclease-AvaI cleavage sites in the bacteriophage-lambda genome. Further evidence for this structure came from the demonstration that DNA fragments generated by endonuclease AvaI can be ligated to form a discrete set of larger molecules and from nearest-neighbor analysis which showed that cytosine residues occurred at the 3'-side of cleavage points. The observation that endonuclease AvaII recognized a subset of the sites recognized by AsuI [Hughes, Bruce & Murray (1979) Biochem. J. 185, 59-63[ led to the deduction that AvaII recognize the pentanucleotide sequence: (Formula: see text), and breaks internucleotide bonds at the positions indicated by the arrows.
mesh_terms: D010582:Bacteriophage lambda; D001483:Base Sequence; D000458:Cyanobacteria / Q000201:enzymology*; D004279:DNA, Viral; D003851:Deoxyribonucleases; D004587:Electrophoresis, Agar Gel; D004590:Electrophoresis, Paper; D004720:Endonucleases; D009838:Oligodeoxyribonucleotides / Q000032:analysis
chemical_list: D004279:DNA, Viral; D009838:Oligodeoxyribonucleotides; D003851:Deoxyribonucleases; D004720:Endonucleases