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==Crystal structure of C. crescentus PNPase bound to RNase E recognition peptide== | |||
<StructureSection load='4aid' size='340' side='right' caption='[[4aid]], [[Resolution|resolution]] 2.60Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4aid]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Cauce Cauce]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AID OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4AID FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></td></tr> | |||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Polyribonucleotide_nucleotidyltransferase Polyribonucleotide nucleotidyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.8 2.7.7.8] </span></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=4aid FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4aid OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4aid RCSB], [http://www.ebi.ac.uk/pdbsum/4aid PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Polynucleotide phosphorylase (PNPase) is an exoribonuclease that cleaves single-stranded RNA substrates with 3'-5' directionality and processive behaviour. Its ring-like, trimeric architecture creates a central channel where phosphorolytic active sites reside. One face of the ring is decorated with RNA-binding K-homology (KH) and S1 domains, but exactly how these domains help to direct the 3' end of single-stranded RNA substrates towards the active sites is an unsolved puzzle. Insight into this process is provided by our crystal structures of RNA-bound and apo Caulobacter crescentus PNPase. In the RNA-free form, the S1 domains adopt a 'splayed' conformation that may facilitate capture of RNA substrates. In the RNA-bound structure, the three KH domains collectively close upon the RNA and direct the 3' end towards a constricted aperture at the entrance of the central channel. The KH domains make non-equivalent interactions with the RNA, and there is a marked asymmetry within the catalytic core of the enzyme. On the basis of these data, we propose that structural non-equivalence, induced upon RNA binding, helps to channel substrate to the active sites through mechanical ratcheting. Structural and biochemical analyses also reveal the basis for PNPase association with RNase E in the multi-enzyme RNA degradosome assembly of the alpha-proteobacteria. | |||
Crystal structure of Caulobacter crescentus polynucleotide phosphorylase reveals a mechanism of RNA substrate channelling and RNA degradosome assembly.,Hardwick SW, Gubbey T, Hug I, Jenal U, Luisi BF Open Biol. 2012 Apr;2(4):120028. PMID:22724061<ref>PMID:22724061</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
== | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
[[Category: Cauce]] | [[Category: Cauce]] | ||
[[Category: Polyribonucleotide nucleotidyltransferase]] | [[Category: Polyribonucleotide nucleotidyltransferase]] | ||
[[Category: Gubbey, T | [[Category: Gubbey, T]] | ||
[[Category: Hardwick, S W | [[Category: Hardwick, S W]] | ||
[[Category: Hug, I | [[Category: Hug, I]] | ||
[[Category: Jenal, U | [[Category: Jenal, U]] | ||
[[Category: Luisi, B F | [[Category: Luisi, B F]] | ||
[[Category: Transferase-peptide complex]] | [[Category: Transferase-peptide complex]] | ||
Revision as of 20:22, 21 December 2014
Crystal structure of C. crescentus PNPase bound to RNase E recognition peptideCrystal structure of C. crescentus PNPase bound to RNase E recognition peptide
Structural highlights
Publication Abstract from PubMedPolynucleotide phosphorylase (PNPase) is an exoribonuclease that cleaves single-stranded RNA substrates with 3'-5' directionality and processive behaviour. Its ring-like, trimeric architecture creates a central channel where phosphorolytic active sites reside. One face of the ring is decorated with RNA-binding K-homology (KH) and S1 domains, but exactly how these domains help to direct the 3' end of single-stranded RNA substrates towards the active sites is an unsolved puzzle. Insight into this process is provided by our crystal structures of RNA-bound and apo Caulobacter crescentus PNPase. In the RNA-free form, the S1 domains adopt a 'splayed' conformation that may facilitate capture of RNA substrates. In the RNA-bound structure, the three KH domains collectively close upon the RNA and direct the 3' end towards a constricted aperture at the entrance of the central channel. The KH domains make non-equivalent interactions with the RNA, and there is a marked asymmetry within the catalytic core of the enzyme. On the basis of these data, we propose that structural non-equivalence, induced upon RNA binding, helps to channel substrate to the active sites through mechanical ratcheting. Structural and biochemical analyses also reveal the basis for PNPase association with RNase E in the multi-enzyme RNA degradosome assembly of the alpha-proteobacteria. Crystal structure of Caulobacter crescentus polynucleotide phosphorylase reveals a mechanism of RNA substrate channelling and RNA degradosome assembly.,Hardwick SW, Gubbey T, Hug I, Jenal U, Luisi BF Open Biol. 2012 Apr;2(4):120028. PMID:22724061[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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