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3k7w

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Revision as of 10:35, 25 December 2014

Protein phosphatase 2A core complex bound to dinophysistoxin-2

Structural highlights

3k7w is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, ,
Related:	2ie4, 3k7v
Gene:	PPP2R1A (Homo sapiens), PPP2CA (Homo sapiens)
Activity:	Phosphoprotein phosphatase, with EC number 3.1.3.16
Resources:	FirstGlance, OCA, RCSB, PDBsum

Function

[2AAA_HUMAN] The PR65 subunit of protein phosphatase 2A serves as a scaffolding molecule to coordinate the assembly of the catalytic subunit and a variable regulatory B subunit. Required for proper chromosome segregation and for centromeric localization of SGOL1 in mitosis.^[1] [PP2AA_HUMAN] PP2A is the major phosphatase for microtubule-associated proteins (MAPs). PP2A can modulate the activity of phosphorylase B kinase casein kinase 2, mitogen-stimulated S6 kinase, and MAP-2 kinase. Cooperates with SGOL2 to protect centromeric cohesin from separase-mediated cleavage in oocytes specifically during meiosis I (By similarity). Can dephosphorylate SV40 large T antigen and p53/TP53. Activates RAF1 by dephosphorylating it at 'Ser-259'.^[2] ^[3] ^[4]

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

Okadaic acid (OA), dinophysistoxin-1 (DTX-1), and dinophysistoxin-2 (DTX-2) are algal toxins that can accumulate in shellfish and cause diarrhetic shellfish poisoning. Recent studies indicate that DTX-2 is about half as toxic and has about half the affinity for protein phosphatase 2A (PP2A) as OA. NMR structural studies showed that DTX-1 possessed an equatorial 35-methyl group but that DTX-2 had an axial 35-methyl group. Molecular modeling studies indicated that an axial 35-methyl could exhibit unfavorable interactions in the PP2A binding site, and this has been proposed as the reason for the reduced toxicity of DTX-2. Statistical analyses of published data indicate that the affinity of PP2A for DTX-1 is 1.6-fold higher, and for DTX-2 is 2-fold lower, than for OA. We obtained X-ray crystal structures of DTX-1 and DTX-2 bound to PP2A. The crystal structures independently confirm the C-35 stereochemistries determined in the earlier NMR study. The structure for the DTX-1 complex was virtually identical to that of the OA-PP2A complex, except for the presence of the equatorial 35-methyl on the ligand. The favorable placement of the equatorial 35-methyl group of DTX-1 against the aromatic pi-bonds of His191 may account for the increased affinity of PP2A toward DTX-1. In contrast, the axial 35-methyl of DTX-2 caused the side chain of His191 to rotate 140 degrees so that it pointed toward the solvent, thereby opening one end of the hydrophobic binding cage. This rearrangement to accommodate the unfavorable interaction from the axial 35-methyl of DTX-2 reduces the binding energy and appears to be responsible for the reduced affinity of PP2A for DTX-2. These results highlight the potential of molecular modeling studies for understanding the relative toxicity of analogues once the binding site at the molecular target has been properly characterized.

A structural basis for the reduced toxicity of dinophysistoxin-2.,Huhn J, Jeffrey PD, Larsen K, Rundberget T, Rise F, Cox NR, Arcus V, Shi Y, Miles CO Chem Res Toxicol. 2009 Nov;22(11):1782-6. PMID:19916524^[5]

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

References

↑ Tang Z, Shu H, Qi W, Mahmood NA, Mumby MC, Yu H. PP2A is required for centromeric localization of Sgo1 and proper chromosome segregation. Dev Cell. 2006 May;10(5):575-85. Epub 2006 Mar 30. PMID:16580887 doi:10.1016/j.devcel.2006.03.010
↑ Hsu W, Zeng L, Costantini F. Identification of a domain of Axin that binds to the serine/threonine protein phosphatase 2A and a self-binding domain. J Biol Chem. 1999 Feb 5;274(6):3439-45. PMID:9920888
↑ Abraham D, Podar K, Pacher M, Kubicek M, Welzel N, Hemmings BA, Dilworth SM, Mischak H, Kolch W, Baccarini M. Raf-1-associated protein phosphatase 2A as a positive regulator of kinase activation. J Biol Chem. 2000 Jul 21;275(29):22300-4. PMID:10801873 doi:10.1074/jbc.M003259200
↑ Watkins GR, Wang N, Mazalouskas MD, Gomez RJ, Guthrie CR, Kraemer BC, Schweiger S, Spiller BW, Wadzinski BE. Monoubiquitination promotes calpain cleavage of the protein phosphatase 2A (PP2A) regulatory subunit alpha4, altering PP2A stability and microtubule-associated protein phosphorylation. J Biol Chem. 2012 Jul 13;287(29):24207-15. doi: 10.1074/jbc.M112.368613. Epub, 2012 May 21. PMID:22613722 doi:10.1074/jbc.M112.368613
↑ Huhn J, Jeffrey PD, Larsen K, Rundberget T, Rise F, Cox NR, Arcus V, Shi Y, Miles CO. A structural basis for the reduced toxicity of dinophysistoxin-2. Chem Res Toxicol. 2009 Nov;22(11):1782-6. PMID:19916524 doi:10.1021/tx9001622

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

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/3k7w"

@@ Line 9: / Line 9: @@
 <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=3k7w FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3k7w OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3k7w RCSB], [http://www.ebi.ac.uk/pdbsum/3k7w PDBsum]</span></td></tr>
 </table>
+== Function ==
+[[http://www.uniprot.org/uniprot/2AAA_HUMAN 2AAA_HUMAN]] The PR65 subunit of protein phosphatase 2A serves as a scaffolding molecule to coordinate the assembly of the catalytic subunit and a variable regulatory B subunit. Required for proper chromosome segregation and for centromeric localization of SGOL1 in mitosis.<ref>PMID:16580887</ref>  [[http://www.uniprot.org/uniprot/PP2AA_HUMAN PP2AA_HUMAN]] PP2A is the major phosphatase for microtubule-associated proteins (MAPs). PP2A can modulate the activity of phosphorylase B kinase casein kinase 2, mitogen-stimulated S6 kinase, and MAP-2 kinase. Cooperates with SGOL2 to protect centromeric cohesin from separase-mediated cleavage in oocytes specifically during meiosis I (By similarity). Can dephosphorylate SV40 large T antigen and p53/TP53. Activates RAF1 by dephosphorylating it at 'Ser-259'.<ref>PMID:9920888</ref> <ref>PMID:10801873</ref> <ref>PMID:22613722</ref>
 == Evolutionary Conservation ==
 [[Image:Consurf_key_small.gif|200px|right]]

3k7w

From Proteopedia

Revision as of 10:35, 25 December 2014

Protein phosphatase 2A core complex bound to dinophysistoxin-2

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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