Exosome
The exosome is the main 3' to 5' Exonuclease in the cell. It is involved in the RNA turnover and processing in the cell. [1]
The exosome is a multisubunit complex. The subunits mean that there is multiple nuclease activites. Rrp44 is used in a large number of diverse RNA processing and degradation events in eukaryotes[2].
Rrp6 is another "nuclear-specific catalytic component of the RNA exosome complex" [3] and is another subunit which provides nuclease activity. The rest of the subunits function in RNA binding/unwinding.