View source for 4rwb


==Racemic influenza M2-TM crystallized from monoolein lipidic cubic phase==
<StructureSection load='4rwb' size='340' side='right'caption='[[4rwb]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4rwb]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Influenza_A_virus_(A/Hong_Kong/156/97(H5N1)) Influenza A virus (A/Hong Kong/156/97(H5N1))]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4RWB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4RWB FirstGlance]. <br>
</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&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=MPG:[(Z)-OCTADEC-9-ENYL]+(2R)-2,3-BIS(OXIDANYL)PROPANOATE'>MPG</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</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=4rwb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4rwb OCA], [https://pdbe.org/4rwb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4rwb RCSB], [https://www.ebi.ac.uk/pdbsum/4rwb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4rwb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/M2_I97A1 M2_I97A1] Forms a proton-selective ion channel that is necessary for the efficient release of the viral genome during virus entry. After attaching to the cell surface, the virion enters the cell by endocytosis. Acidification of the endosome triggers M2 ion channel activity. The influx of protons into virion interior is believed to disrupt interactions between the viral ribonucleoprotein (RNP), matrix protein 1 (M1), and lipid bilayers, thereby freeing the viral genome from interaction with viral proteins and enabling RNA segments to migrate to the host cell nucleus, where influenza virus RNA transcription and replication occur. Also plays a role in viral proteins secretory pathway. Elevates the intravesicular pH of normally acidic compartments, such as trans-Golgi network, preventing newly formed hemagglutinin from premature switching to the fusion-active conformation.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Interactions between polypeptide chains containing amino acid residues with opposite absolute configurations have long been a source of interest and speculation, but there is very little structural information for such heterochiral associations. The need to address this lacuna has grown in recent years because of increasing interest in the use of peptides generated from d amino acids (d peptides) as specific ligands for natural proteins, e.g., to inhibit deleterious protein-protein interactions. Coiled-coil interactions, between or among alpha-helices, represent the most common tertiary and quaternary packing motif in proteins. Heterochiral coiled-coil interactions were predicted over 50 years ago by Crick, and limited experimental data obtained in solution suggest that such interactions can indeed occur. To address the dearth of atomic-level structural characterization of heterochiral helix pairings, we report two independent crystal structures that elucidate coiled-coil packing between l- and d-peptide helices. Both structures resulted from racemic crystallization of a peptide corresponding to the transmembrane segment of the influenza M2 protein. Networks of canonical knobs-into-holes side-chain packing interactions are observed at each helical interface. However, the underlying patterns for these heterochiral coiled coils seem to deviate from the heptad sequence repeat that is characteristic of most homochiral analogs, with an apparent preference for a hendecad repeat pattern.

High-resolution structures of a heterochiral coiled coil.,Mortenson DE, Steinkruger JD, Kreitler DF, Perroni DV, Sorenson GP, Huang L, Mittal R, Yun HG, Travis BR, Mahanthappa MK, Forest KT, Gellman SH Proc Natl Acad Sci U S A. 2015 Oct 27;112(43):13144-9. doi:, 10.1073/pnas.1507918112. Epub 2015 Oct 12. PMID:26460035<ref>PMID:26460035</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4rwb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ion channels 3D structures|Ion channels 3D structures]]
*[[M2 protein|M2 protein]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Forest KT]]
[[Category: Gellman SH]]
[[Category: Kreitler DF]]
[[Category: Mortenson DE]]
[[Category: Steinkruger JD]]