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1yf8

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Revision as of 23:12, 10 September 2015

Crystal structure of Himalayan mistletoe RIP reveals the presence of a natural inhibitor and a new functionally active sugar-binding site

Structural highlights

1yf8 is a 2 chain structure with sequence from Viscum album. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, , , , ,
Activity:	rRNA N-glycosylase, with EC number 3.2.2.22
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum

Function

[ML4_VISAL] The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. The B chain binds to cell receptors and probably facilitates the entry into the cell of the A chain; B chains are also responsible for cell agglutination (lectin activity). Inhibits growth of the human tumor cell line Molt4.^[1] ^[2] [UniProtKB:P81446]

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

Ribosome-inactivating proteins (RIPs) are toxins involved in plant defense. How the plant prevents autotoxicity is not yet fully understood. The present study is the first structural evidence of a naturally inhibited form of RIP from a plant. Himalayan mistletoe RIP (HmRIP) was purified from Viscum album leaves and crystallized with lactose. The structure was determined by the molecular replacement method and refined at 2.8-A resolution. The crystal structure revealed the presence of high quality non-protein electron density at the active site, into which a pteridine derivative (2-amino 4-isopropyl 6-carboxyl pteridine) was modeled. The carboxyl group of the ligand binds strongly with the key active site residue Arg(162), nullifies the positive charge required for catalysis, and thereby acts as a natural inhibitor. Lectin subunits of RIPs have two active sugar-binding sites present in 1alpha- and 2gamma-subdomains. A third functionally active site has been identified in the 1beta-subdomain of HmRIP. The 1beta-site is active despite the absence of conserved polar sugar-binding residues. Loss of these residues is compensated by the following: (i) the presence of an extended site where the penultimate sugar also interacts with the protein; (ii) the interactions of galactose with the protein main chain carbonyl and amide nitrogen atoms; (iii) the presence of a well defined pocket encircled by four walls; and (iv) a favorable stacking of the galactose ring with Tyr(66) besides the conserved Phe(75). The mode of sugar binding is also distinct at the 1alpha and 2gamma sugar-binding sites.

Crystal structure of himalayan mistletoe ribosome-inactivating protein reveals the presence of a natural inhibitor and a new functionally active sugar-binding site.,Mishra V, Bilgrami S, Sharma RS, Kaur P, Yadav S, Krauspenhaar R, Betzel C, Voelter W, Babu CR, Singh TP J Biol Chem. 2005 May 27;280(21):20712-21. Epub 2005 Mar 17. PMID:15774467^[3]

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

References

↑ Mishra V, Sharma RS, Yadav S, Babu CR, Singh TP. Purification and characterization of four isoforms of Himalayan mistletoe ribosome-inactivating protein from Viscum album having unique sugar affinity. Arch Biochem Biophys. 2004 Mar 15;423(2):288-301. PMID:15001393 doi:http://dx.doi.org/10.1016/j.abb.2003.12.033
↑ Dietrich JB, Ribereau-Gayon G, Jung ML, Franz H, Beck JP, Anton R. Identity of the N-terminal sequences of the three A chains of mistletoe (Viscum album L.) lectins: homology with ricin-like plant toxins and single-chain ribosome-inhibiting proteins. Anticancer Drugs. 1992 Oct;3(5):507-11. PMID:1450445
↑ Mishra V, Bilgrami S, Sharma RS, Kaur P, Yadav S, Krauspenhaar R, Betzel C, Voelter W, Babu CR, Singh TP. Crystal structure of himalayan mistletoe ribosome-inactivating protein reveals the presence of a natural inhibitor and a new functionally active sugar-binding site. J Biol Chem. 2005 May 27;280(21):20712-21. Epub 2005 Mar 17. PMID:15774467 doi:10.1074/jbc.M500735200

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

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1yf8"

@@ Line 5: / Line 5: @@
 </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=P6C:2-AMINO-4-ISOPROPYL-PTERIDINE-6-CARBOXYLIC+ACID'>P6C</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene></td></tr>
 <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/rRNA_N-glycosylase rRNA N-glycosylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.22 3.2.2.22] </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=1yf8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1yf8 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1yf8 RCSB], [http://www.ebi.ac.uk/pdbsum/1yf8 PDBsum]</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=1yf8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1yf8 OCA], [http://pdbe.org/1yf8 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1yf8 RCSB], [http://www.ebi.ac.uk/pdbsum/1yf8 PDBsum]</span></td></tr>
 </table>
 == Function ==
@@ Line 27: / Line 27: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 1yf8" style="background-color:#fffaf0;"></div>
 == References ==
 <references/>

1yf8

From Proteopedia

Revision as of 23:12, 10 September 2015

Crystal structure of Himalayan mistletoe RIP reveals the presence of a natural inhibitor and a new functionally active sugar-binding site

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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