The calf 5'- to 3'-exonuclease is also an endonuclease with both activities dependent on primers annealed upstream of the point of cleavage

摘要: Abstract The catalytic activity of the calf thymus 5'- to 3'-exonuclease was measured on substrates consisting two primers annealed adjacent each other a template. Exonucleolytic degradation downstream primer is very slow if are separated by gap one nucleotide or no upstream present. When only nick separates primers, rapid. This suggests that nuclease designed work with DNA polymerases such synthesis from an creates favored substrate. Nuclease action then destroys substrate, but it regenerated further polymerization. process, termed translation, necessary for both replication and repair. If has unannealed 5'-region, region removed endonuclease residing in same enzyme. Efficient also requires its 3'-end directly primer. reaction likely be important removal segments damaged exonuclease cleavage site not possible.