The presence of partially degraded RNA suggests that endonucleases rather than exonucleases
are primarily involved in the degradation of salivary RNA, because exonucleases
are usually processive, degrading the target RNA substrates completely or giving rise to significant degradation on one end of the mRNA, as has been shown for plasma RNA (26).
The most obvious of these is the nearly immediate degradation of normal phosphodiester-linked nucleotides by the exonucleases
abundant both in serum and within cells.
Accordingly, enzymes called exonucleases
pick up where UDGases and other base cutters leave off, excising damaged nucleotides.
Cellectis's teams thus succeeded in improving current genome engineering techniques by employing a new approach: co-expressing meganucleases or TALENs[TM], Cellectis's internal technology, together with exonucleases
Mismatch repair is a complex process that depends on MMR proteins and multiple proteins that interact directly with DNA (single-stranded DNA-binding protein; exonucleases
I, VII, and X; RecJ exonuclease
; DNA helicase II; DNA polymerase III; and DNA ligase).