2A1S

Crystal structure of native PARN nuclease domain

Summary for 2A1S

• Entry DOI: 10.2210/pdb2a1s/pdb
• Related: 2A1R
• Descriptor: Poly(A)-specific ribonuclease PARN (2 entities in total)
• Functional Keywords: parn, dedd, nuclease domain, r3h, hydrolase
• Biological source: Homo sapiens (human)
• Cellular location: Nucleus: O95453
• Total number of polymer chains: 4
• Total formula weight: 198468.55

Authors

Wu, M.,Song, H. (deposition date: 2005-06-21, release date: 2005-12-20, Last modification date: 2023-10-25)

Primary citation

Wu, M.,Reuter, M.,Lilie, H.,Liu, Y.,Wahle, E.,Song, H.
Structural insight into poly(A) binding and catalytic mechanism of human PARN
Embo J., 24:4082-4093, 2005

PubMed Abstract: Poly(A)-specific ribonuclease (PARN) is a processive, poly(A)-specific 3' exoribonuclease. The crystal structure of C-terminal truncated human PARN determined in two states (free and RNA-bound forms) reveals that PARNn is folded into two domains, an R3H domain and a nuclease domain similar to those of Pop2p and epsilon186. The high similarity of the active site structures of PARNn and epsilon186 suggests that they may have a similar catalytic mechanism. PARNn forms a tight homodimer, with the R3H domain of one subunit partially enclosing the active site of the other subunit and poly(A) bound in a deep cavity of its nuclease domain in a sequence-nonspecific manner. The R3H domain and, possibly, the cap-binding domain are involved in poly(A) binding but these domains alone do not appear to contribute to poly(A) specificity. Mutations disrupting dimerization abolish both the enzymatic and RNA-binding activities, suggesting that the PARN dimer is a structural and functional unit. The cap-binding domain may act in concert with the R3H domain to amplify the processivity of PARN.

PubMed: 16281054
DOI: 10.1038/sj.emboj.7600869

Experimental method

X-RAY DIFFRACTION (2.6 Å)