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| | {{STRUCTURE_1r9u| PDB=1r9u | SCENE= }} | | {{STRUCTURE_1r9u| PDB=1r9u | SCENE= }} |
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| - | '''Refined structure of peptaibol zervamicin IIB in methanol solution from trans-hydrogen bond J couplings'''
| + | ===Refined structure of peptaibol zervamicin IIB in methanol solution from trans-hydrogen bond J couplings=== |
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| - | ==Overview==
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| - | Zervamicin IIB (Zrv-IIB) is a channel-forming peptaibol antibiotic of fungal origin. The measured transhydrogen bond (3h)J(NC') couplings in methanol solution heaving average value of -0.41 Hz indicate that the stability of the Zrv-IIB helix in this milieu is comparable to the stability of helices in globular proteins. The N-terminus of the peptide forms an alpha-helix, whereas 3(10)-helical hydrogen bonds stabilize the C-terminus. However, two weak transhydrogen bond peaks are observed in a long-range HNCO spectrum for HN Aib(12). Energy calculations using the Empirical Conformation Energy Program for Peptides (ECEPP)/2 force field and the implicit solvent model show that the middle of the peptide helix accommodates a bifurcated hydrogen bond that is simultaneously formed between HN Aib(12) and CO Leu(8) and CO Aib(9). Several lowered (3h)J(NC') on a polar face of the helix correlate with the conformational exchange process observed earlier and imply dynamic distortions of a hydrogen bond pattern with the predominant population of a properly folded helical structure. The refined structure of Zrv-IIB on the basis of the observed hydrogen bond pattern has a small ( approximately 20 degrees ) angle of helix bending that is virtually identical to the angle of bending in dodecylphosphocholine (DPC) micelles, indicating the stability of a hinge region in different environments. NMR parameters ((1)HN chemical shifts and transpeptide bond (1)J(NC') couplings) sensitive to hydrogen bonding along with the solvent accessible surface area of carbonyl oxygens indicate a large polar patch on the convex side of the helix formed by three exposed backbone carbonyls of Aib(7), Aib(9), and Hyp(10) and polar side chains of Hyp(10), Gln(11), and Hyp(13). The unique structural features, high helix stability and the enhanced polar patch, set apart Zrv-IIB from other peptaibols (for example, alamethicin) and possibly underlie its biological and physiological properties.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_15189865}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 15189865 is the PubMed ID number. |
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| | + | {{ABSTRACT_PUBMED_15189865}} |
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| | ==About this Structure== | | ==About this Structure== |
| - | Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1R9U OCA]. | + | Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1R9U OCA]. |
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| | ==Reference== | | ==Reference== |
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| | [[Category: Bent helix]] | | [[Category: Bent helix]] |
| | [[Category: Bifurcated hydrogen bond]] | | [[Category: Bifurcated hydrogen bond]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 07:15:06 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Jul 27 16:49:16 2008'' |
Revision as of 13:49, 27 July 2008
Template:STRUCTURE 1r9u
Refined structure of peptaibol zervamicin IIB in methanol solution from trans-hydrogen bond J couplings
Template:ABSTRACT PUBMED 15189865
About this Structure
Full experimental information is available from OCA.
Reference
Peptaibol zervamicin IIb structure and dynamics refinement from transhydrogen bond J couplings., Shenkarev ZO, Balashova TA, Yakimenko ZA, Ovchinnikova TV, Arseniev AS, Biophys J. 2004 Jun;86(6):3687-99. PMID:15189865
Page seeded by OCA on Sun Jul 27 16:49:16 2008
