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.

1kv0

From Proteopedia

(Difference between revisions)

Jump to: navigation, search

Revision as of 08:37, 11 September 2015

Cis/trans Isomerization of Non-prolyl Peptide Bond Observed in Crystal Structure of an Scorpion Toxin

Structural highlights

1kv0 is a 2 chain structure with sequence from Mesobuthus martensii. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Related:	1sn1, 1sn4, 1chz, 1djt
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum

Function

[SCX7_MESMA] Binds to sodium channels (Nav) and inhibits the inactivation of the activated channels, thereby blocking neuronal transmission. Is active on both mammals and insects. Can be considered as a cardiotoxin, as it can bind to human cardiac sodium channel and modify its normal properties.^[1]

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

Non-proline cis peptide bonds have been observed in numerous protein crystal structures even though the energetic barrier to this conformation is significant and no non-prolyl-cis/trans-isomerase has been identified to date. While some external factors, such as metal binding or co-factor interaction, have been identified that appear to induce cis/trans isomerization of non-proline peptide bonds, the intrinsic structural basis for their existence and the mechanism governing cis/trans isomerization in proteins remains poorly understood. Here, we report the crystal structure of a newly isolated neurotoxin, the scorpion alpha-like toxin Buthus martensii Karsch (BmK) M7, at 1.4A resolution. BmK M7 crystallizes as a dimer in which the identical non-proline peptide bond between residues 9 and 10 exists either in the cis conformation or as a mixture of cis and trans conformations in either monomer. We also determined the crystal structures of several mutants of BmK M1, a representative scorpion alpha-like toxin that contains an identical non-proline cis peptide bond as that observed in BmK M7, in which residues within or neighboring the cis peptide bond were altered. Substitution of an aspartic acid residue for lysine at residue 8 in the BmK M1 (K8D) mutant converted the cis form of the non-proline peptide bond 9-10 into the trans form, revealing an intramolecular switch for cis-to-trans isomerization. Cis/trans interconversion of the switch residue at position 8 appears to be sequence-dependent as the peptide bond between residues 9 and 10 retains its wild-type cis conformation in the BmK M1 (K8Q) mutant structure. The structural interconversion of the isomeric states of the BmK M1 non-proline cis peptide bond may relate to the conversion of the scorpion alpha-toxins subgroups.

Structural mechanism governing cis and trans isomeric states and an intramolecular switch for cis/trans isomerization of a non-proline peptide bond observed in crystal structures of scorpion toxins.,Guan RJ, Xiang Y, He XL, Wang CG, Wang M, Zhang Y, Sundberg EJ, Wang DC J Mol Biol. 2004 Aug 27;341(5):1189-204. PMID:15321715^[2]

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

References

↑ Guan RJ, He XL, Wang M, Ye-Xiang, Li GP, Wang DC. Purification, crystallization and initial structural solution of a new alpha-like toxin with cardiac toxicity from scorpion Buthus martensii Karsch. Protein Pept Lett. 2002 Oct;9(5):441-9. PMID:12370033
↑ Guan RJ, Xiang Y, He XL, Wang CG, Wang M, Zhang Y, Sundberg EJ, Wang DC. Structural mechanism governing cis and trans isomeric states and an intramolecular switch for cis/trans isomerization of a non-proline peptide bond observed in crystal structures of scorpion toxins. J Mol Biol. 2004 Aug 27;341(5):1189-204. PMID:15321715 doi:http://dx.doi.org/10.1016/j.jmb.2004.06.067

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/1kv0"

@@ Line 4: / Line 4: @@
 <table><tr><td colspan='2'>[[1kv0]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Mesobuthus_martensii Mesobuthus martensii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KV0 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1KV0 FirstGlance]. <br>
 </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1sn1|1sn1]], [[1sn4|1sn4]], [[1chz|1chz]], [[1djt|1djt]]</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=1kv0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kv0 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1kv0 RCSB], [http://www.ebi.ac.uk/pdbsum/1kv0 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=1kv0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kv0 OCA], [http://pdbe.org/1kv0 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1kv0 RCSB], [http://www.ebi.ac.uk/pdbsum/1kv0 PDBsum]</span></td></tr>
 </table>
 == Function ==
@@ Line 26: / Line 26: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 1kv0" style="background-color:#fffaf0;"></div>
 == References ==
 <references/>

1kv0

From Proteopedia

Revision as of 08:37, 11 September 2015

Cis/trans Isomerization of Non-prolyl Peptide Bond Observed in Crystal Structure of an Scorpion Toxin

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

Personal tools

Navigation

Search

Toolbox