Crystallographic structure of the nuclease domain of 3'hExo, a DEDDh family member, bound to rAMPCrystallographic structure of the nuclease domain of 3'hExo, a DEDDh family member, bound to rAMP

Structural highlights

1w0h is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.59Å
Ligands:, ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

ERI1_HUMAN RNA exonuclease that binds to the 3'-end of histone mRNAs and degrades them, suggesting that it plays an essential role in histone mRNA decay after replication. A 2' and 3'-hydroxyl groups at the last nucleotide of the histone 3'-end is required for efficient degradation of RNA substrates. Also able to degrade the 3'-overhangs of short interfering RNAs (siRNAs) in vitro, suggesting a possible role as regulator of RNA interference (RNAi). Requires for binding the 5'-ACCCA-3' sequence present in stem-loop structure. Able to bind other mRNAs. Required for 5.8S rRNA 3'-end processing. Also binds to 5.8s ribosomal RNA. Binds with high affinity to the stem-loop structure of replication-dependent histone pre-mRNAs.[1] [2]

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

A human 3'-5'-exoribonuclease (3'hExo) has recently been identified and shown to be responsible for histone mRNA degradation. Functionally, 3'hExo and a stem-loop binding protein (SLBP) target opposite faces of a unique highly conserved stem-loop RNA scaffold towards the 3' end of histone mRNA, which is composed of a 6 bp stem and a 4 nt loop, followed by an ACCCA sequence. Its Caenorhabditis elegans homologue, ERI-1, has been shown to degrade small interfering RNA in vitro and to function as a negative regulator of RNA interference in neuronal cells. We have determined the structure of the nuclease domain (Nuc) of 3'hExo complexed with rAMP in the presence of Mg2+ at 1.6 A resolution. The Nuc domain adopts an alpha/beta globular fold, with four acidic residues coordinating a binuclear metal cluster within the active site, whose topology is related to DEDDh exonuclease family members, despite a very low level of primary sequence identity. The two magnesium cations in the Nuc active site are coordinated to D134, E136, D234 and D298, and together with H293, which can potentially act as a general base, provide a platform for hydrolytic cleavage of bound RNA in the 3' --> 5' direction. The bound rAMP is positioned within a deep active-site pocket, with its purine ring close-packed with the hydrophobic F185 and L189 side-chains and its sugar 2'-OH and 3'-OH groups hydrogen bonded to backbone atoms of Nuc. There are striking similarities between the active sites of Nuc and epsilon186, an Escherichia coli DNA polymerase III proofreading domain, providing a common hydrolytic cleavage mechanism for RNA degradation and DNA editing, respectively.

Crystallographic structure of the nuclease domain of 3'hExo, a DEDDh family member, bound to rAMP.,Cheng Y, Patel DJ J Mol Biol. 2004 Oct 15;343(2):305-12. PMID:15451662[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Dominski Z, Yang XC, Kaygun H, Dadlez M, Marzluff WF. A 3' exonuclease that specifically interacts with the 3' end of histone mRNA. Mol Cell. 2003 Aug;12(2):295-305. PMID:14536070
  2. Yang XC, Purdy M, Marzluff WF, Dominski Z. Characterization of 3'hExo, a 3' exonuclease specifically interacting with the 3' end of histone mRNA. J Biol Chem. 2006 Oct 13;281(41):30447-54. Epub 2006 Aug 15. PMID:16912046 doi:10.1074/jbc.M602947200
  3. Cheng Y, Patel DJ. Crystallographic structure of the nuclease domain of 3'hExo, a DEDDh family member, bound to rAMP. J Mol Biol. 2004 Oct 15;343(2):305-12. PMID:15451662 doi:10.1016/j.jmb.2004.08.055

1w0h, resolution 1.59Å

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