==X-RAY CRYSTAL STRUCTURE OF THE POLY(A)-BINDING PROTEIN IN COMPLEX WITH POLYADENYLATE RNA==

<StructureSection load='1cvj' size='340' side='right'caption='[[1cvj]], [[Resolution|resolution]] 2.60&Aring;' scene=''>

<table><tr><td colspan='2'>[[1cvj]] is a 16 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. The October 2008 RCSB PDB [http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Poly(A) Polymerase'' by David Goodsell is [http://dx.doi.org/10.2210/rcsb_pdb/mom_2008_10 10.2210/rcsb_pdb/mom_2008_10]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CVJ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1CVJ FirstGlance]. <br>

</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1cvj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1cvj OCA], [http://pdbe.org/1cvj PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1cvj RCSB], [http://www.ebi.ac.uk/pdbsum/1cvj PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1cvj ProSAT]</span></td></tr>

== Function ==

[[http://www.uniprot.org/uniprot/PABP1_HUMAN PABP1_HUMAN]] Binds the poly(A) tail of mRNA. May be involved in cytoplasmic regulatory processes of mRNA metabolism such as pre-mRNA splicing. Its function in translational initiation regulation can either be enhanced by PAIP1 or repressed by PAIP2. Can probably bind to cytoplasmic RNA sequences other than poly(A) in vivo. Involved in translationally coupled mRNA turnover. Implicated with other RNA-binding proteins in the cytoplasmic deadenylation/translational and decay interplay of the FOS mRNA mediated by the major coding-region determinant of instability (mCRD) domain. Involved in regulation of nonsense-mediated decay (NMD) of mRNAs containing premature stop codons; for the recognition of premature termination codons (PTC) and initiation of NMD a competitive interaction between UPF1 and PABPC1 with the ribosome-bound release factors is proposed.<ref>PMID:11051545</ref> <ref>PMID:18447585</ref>

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

The cocrystal structure of human poly(A)-binding protein (PABP) has been determined at 2.6 A resolution. PABP recognizes the 3' mRNA poly(A) tail and plays critical roles in eukaryotic translation initiation and mRNA stabilization/degradation. The minimal PABP used in this study consists of the N-terminal two RRM-type RNA-binding domains connected by a short linker (RRM1/2). These two RRMs form a continuous RNA-binding trough, lined by an antiparallel beta sheet backed by four alpha helices. The polyadenylate RNA adopts an extended conformation running the length of the molecular trough. Adenine recognition is primarily mediated by contacts with conserved residues found in the RNP motifs of the two RRMs. The convex dorsum of RRM1/2 displays a phylogenetically conserved hydrophobic/acidic portion, which may interact with translation initiation factors and regulatory proteins.

Recognition of polyadenylate RNA by the poly(A)-binding protein.,Deo RC, Bonanno JB, Sonenberg N, Burley SK Cell. 1999 Sep 17;98(6):835-45. PMID:10499800<ref>PMID:10499800</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

</div>

<div class="pdbe-citations 1cvj" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Human]]

[[Category: RCSB PDB Molecule of the Month]]

[[Category: Gene regulation-rna complex]]

[[Category: Rrm]]