Mismatch and blunt to protruding-end joining by DNA ligases.
A nuclear DNA ligase activity from immature chicken erythrocytes, and to a lesser extent T4-induced DNA ligase, can join cohesive-ends (3 and 5-nucleotides long) having one of the mismatches, A/A, T/T, C/C, G/G, at the middle position. The rate of ligation depends on the length and stability of the mispaired intermediate (G/G, T/T greater than A/A, C/C). When the non-complementary overhanging-ends are short (i.e. 1-nucleotide) both ligases catalyze the joining of the single-stranded protruding-end with a blunt-end. This reaction occurs at low but significant rates compared to blunt-end ligation. The chicken ligase has lower flush-end joining activity than T4 DNA ligase, but it is more permissive since it joins C/C or A/A mismatched-ends, whereas the prokaryotic ligase does not. Possible biological implications of the reactions are discussed. We have also found that BstEII easily cleaves at sites harboring a C/C or a G/G mismatch at the center of its recognition sequence, whereas AvaII (T/T or A/A), HinfI (G/G) and DdeI (G/G) do not.
Wiaderkiewicz
R
R
Cancer Research Center, Laval University School of Medicine, Québec, Canada.
Ruiz-Carrillo
A
A
D000818:Animals; D001482:Base Composition; D002645:Chickens / Q000097:blood; D004247:DNA / Q000378:metabolism; D011088:DNA Ligases / Q000302:isolation & purification / Q000378:metabolism*; D004262:DNA Restriction Enzymes; D004912:Erythrocytes / Q000201:enzymology; D008954:Models, Biological; D011118:Polynucleotide Ligases / Q000378:metabolism*; D013816:Thermodynamics; D014764:Viral Proteins / Q000378:metabolism
D014764:Viral Proteins; D004247:DNA; D004262:DNA Restriction Enzymes; D011088:DNA Ligases; D011118:Polynucleotide Ligases