This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.

4x4w

From Proteopedia

(Difference between revisions)

Jump to: navigation, search

Revision as of 09:32, 22 November 2017

Crystal structure of the full-length human mitochondrial CCA-adding enzyme

Structural highlights

4x4w is a 2 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, , ,
Gene:	TRNT1, CGI-47 (HUMAN)
Activity:	CCA tRNA nucleotidyltransferase, with EC number 2.7.7.72
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[TRNT1_HUMAN] Isoform 1: Adds and repairs the conserved 3'-CCA sequence necessary for the attachment of amino acids to the 3' terminus of tRNA molecules, using CTP and ATP as substrates.^[1] Isoform 2: Adds 2 C residues (CC-) to the 3' terminus of tRNA molecules instead of a complete CCA end as isoform 1 does (in vitro).^[2]

Publication Abstract from PubMed

Transcription in eukaryotes produces a number of long noncoding RNAs (lncRNAs). Two of these, MALAT1 and Menbeta, generate a tRNA-like small RNA in addition to the mature lncRNA. The stability of these tRNA-like small RNAs and bona fide tRNAs is monitored by the CCA-adding enzyme. Whereas CCA is added to stable tRNAs and tRNA-like transcripts, a second CCA repeat is added to certain unstable transcripts to initiate their degradation. Here, we characterize how these two scenarios are distinguished. Following the first CCA addition cycle, nucleotide binding to the active site triggers a clockwise screw motion, producing torque on the RNA. This ejects stable RNAs, whereas unstable RNAs are refolded while bound to the enzyme and subjected to a second CCA catalytic cycle. Intriguingly, with the CCA-adding enzyme acting as a molecular vise, the RNAs proofread themselves through differential responses to its interrogation between stable and unstable substrates.

On-Enzyme Refolding Permits Small RNA and tRNA Surveillance by the CCA-Adding Enzyme.,Kuhn CD, Wilusz JE, Zheng Y, Beal PA, Joshua-Tor L Cell. 2015 Feb 12;160(4):644-58. doi: 10.1016/j.cell.2015.01.005. Epub 2015 Jan, 29. PMID:25640237^[3]

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

References

↑ Lizano E, Schuster J, Muller M, Kelso J, Morl M. A splice variant of the human CCA-adding enzyme with modified activity. J Mol Biol. 2007 Mar 2;366(4):1258-65. Epub 2006 Dec 12. PMID:17204286 doi:http://dx.doi.org/10.1016/j.jmb.2006.12.016
↑ Lizano E, Schuster J, Muller M, Kelso J, Morl M. A splice variant of the human CCA-adding enzyme with modified activity. J Mol Biol. 2007 Mar 2;366(4):1258-65. Epub 2006 Dec 12. PMID:17204286 doi:http://dx.doi.org/10.1016/j.jmb.2006.12.016
↑ Kuhn CD, Wilusz JE, Zheng Y, Beal PA, Joshua-Tor L. On-Enzyme Refolding Permits Small RNA and tRNA Surveillance by the CCA-Adding Enzyme. Cell. 2015 Feb 12;160(4):644-58. doi: 10.1016/j.cell.2015.01.005. Epub 2015 Jan, 29. PMID:25640237 doi:http://dx.doi.org/10.1016/j.cell.2015.01.005

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4x4w"

@@ Line 3: / Line 3: @@
 <StructureSection load='4x4w' size='340' side='right' caption='[[4x4w]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[4x4w]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4X4W OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4X4W FirstGlance]. <br>
+<table><tr><td colspan='2'>[[4x4w]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4X4W OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4X4W FirstGlance]. <br>
 </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=FLC:CITRATE+ANION'>FLC</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
+<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">TRNT1, CGI-47 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr>
 <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/CCA_tRNA_nucleotidyltransferase CCA tRNA nucleotidyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.72 2.7.7.72] </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=4x4w FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4x4w OCA], [http://pdbe.org/4x4w PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4x4w RCSB], [http://www.ebi.ac.uk/pdbsum/4x4w PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4x4w ProSAT]</span></td></tr>
@@ Line 19: / Line 20: @@
 </div>
 <div class="pdbe-citations 4x4w" style="background-color:#fffaf0;"></div>
-==See Also==
-*[[CCA-adding enzyme|CCA-adding enzyme]]
 == References ==
 <references/>
@@ Line 27: / Line 25: @@
 </StructureSection>
 [[Category: CCA tRNA nucleotidyltransferase]]
+[[Category: Human]]
 [[Category: Joshua-Tor, L]]
 [[Category: Kuhn, C D]]

4x4w

From Proteopedia

Revision as of 09:32, 22 November 2017

Crystal structure of the full-length human mitochondrial CCA-adding enzyme

Structural highlights

Function

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

Personal tools

Navigation

Search

Toolbox