Nuclear-specific catalytic component of the RNA exosome complex which has 3'->5' exoribonuclease activity and participates in a multitude of cellular RNA processing and degradation events. In the nucleus, the RNA exosome complex is involved in proper maturation of stable RNA species such as rRNA, snRNA and snoRNA, in the elimination of RNA processing by-products and non-coding 'pervasive' transcripts, such as antisense RNA species and cryptic unstable transcripts (CUTs), and of mRNAs with processing defects, thereby limiting or excluding their export to the cytoplasm. The catalytic inactive RNA exosome core complex of 9 subunits (Exo-9) is proposed to play a pivotal role in the binding and presentation of RNA for ribonucleolysis, and to serve as a scaffold for the association with catalytic subunits and accessory proteins or complexes. RRP6 has 3'-5' exonuclease activity which is not modulated upon association with Exo-9 suggesting that the complex inner RNA-binding path is not used to access its active site. Component of the RNA exosome complex. The catalytically inactive RNA exosome core (Exo-9) complex associates with catalytic subunits DIS3 and RRP6 in cytoplasmic- and nuclear-specific RNA exosome complex forms. Exo-9 is formed by a hexameric ring of RNase PH domain-containing subunits and peripheral S1 domain-containing components CSL4, RRP4 and RRP40 located on the top of the ring structure. RRP6 specifically is part of the nuclear form of the RNA exosome complex; the association appears to be mediated by Exo-9 and not by DIS3. Interacts with LRP1. Interacts with NPL3, NOP53 and PAP1. Deletion mutant is impaired in growth at all temperatures and is nonviable at 37 degrees Celsius. It is defective in the 3' processing of the 5.8S rRNA and accumulates a discrete species, 5.8S + 30, that is 3' extended by about 30 nucleotides. Deletion also causes an accumulation of 7S RNA and 5' ETS and increases the level of poly(A)+ mRNA. Present with 2160 molecules/cell in log phase SD medium. Belongs to the exosome component 10/RRP6 family.