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| | == Structural highlights == | | == Structural highlights == |
| | <table><tr><td colspan='2'>[[1yf8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Viscum_album Viscum album]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YF8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1YF8 FirstGlance]. <br> | | <table><tr><td colspan='2'>[[1yf8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Viscum_album Viscum album]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YF8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1YF8 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.8Å</td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/rRNA_N-glycosylase rRNA N-glycosylase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.22 3.2.2.22] </span></td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=MAN:ALPHA-D-MANNOSE'>MAN</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=PRD_900004:beta-lactose'>PRD_900004</scene></td></tr> |
| | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1yf8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1yf8 OCA], [https://pdbe.org/1yf8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1yf8 RCSB], [https://www.ebi.ac.uk/pdbsum/1yf8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1yf8 ProSAT]</span></td></tr> | | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1yf8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1yf8 OCA], [https://pdbe.org/1yf8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1yf8 RCSB], [https://www.ebi.ac.uk/pdbsum/1yf8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1yf8 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[https://www.uniprot.org/uniprot/ML4_VISAL 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.<ref>PMID:15001393</ref> <ref>PMID:1450445</ref> [UniProtKB:P81446]
| + | [https://www.uniprot.org/uniprot/ML4_VISAL 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.<ref>PMID:15001393</ref> <ref>PMID:1450445</ref> [UniProtKB:P81446] |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| | [[Category: Viscum album]] | | [[Category: Viscum album]] |
| - | [[Category: RRNA N-glycosylase]]
| + | [[Category: Babu CR]] |
| - | [[Category: Babu, C R]] | + | [[Category: Betzel C]] |
| - | [[Category: Betzel, C]] | + | [[Category: Bilgrami S]] |
| - | [[Category: Bilgrami, S]] | + | [[Category: Kaur P]] |
| - | [[Category: Kaur, P]] | + | [[Category: Mishra V]] |
| - | [[Category: Mishra, V]] | + | [[Category: Sharma RS]] |
| - | [[Category: Sharma, R S]] | + | [[Category: Singh TP]] |
| - | [[Category: Singh, T P]] | + | [[Category: Yadav S]] |
| - | [[Category: Yadav, S]] | + | |
| - | [[Category: Himalayan mistletoe]]
| + | |
| - | [[Category: Hydrolase]]
| + | |
| - | [[Category: Natural inhibitor]]
| + | |
| - | [[Category: Ribosome inactivating protein]]
| + | |
| - | [[Category: 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.
| | Method: | X-ray diffraction, Resolution 2.8Å |
| Ligands: | , , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
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
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