View source for 7zcu


==PucA-LH2 complex from Rps. palustris==
<StructureSection load='7zcu' size='340' side='right'caption='[[7zcu]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7zcu]] is a 19 chain structure with sequence from [https://en.wikipedia.org/wiki/Rhodopseudomonas_palustris_ATCC_17001 Rhodopseudomonas palustris ATCC 17001]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7ZCU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7ZCU FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CXM:N-CARBOXYMETHIONINE'>CXM</scene>, <scene name='pdbligand=IRM:(6~{E},8~{E},10~{E},12~{E},14~{E},16~{E},18~{E},20~{E},22~{E},24~{E},26~{E})-2,6,10,14,19,23,27,31-octamethyldotriaconta-6,8,10,12,14,16,18,20,22,24,26,30-dodecaen-2-ol'>IRM</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=7zcu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7zcu OCA], [https://pdbe.org/7zcu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7zcu RCSB], [https://www.ebi.ac.uk/pdbsum/7zcu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7zcu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q6N9P5_RHOPA Q6N9P5_RHOPA] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The genomes of some purple photosynthetic bacteria contain a multigene puc family encoding a series of alpha- and beta-polypeptides that together form a heterogeneous antenna of light-harvesting 2 (LH2) complexes. To unravel this complexity, we generated four sets of puc deletion mutants in Rhodopseudomonas palustris, each encoding a single type of pucBA gene pair and enabling the purification of complexes designated as PucA-LH2, PucB-LH2, PucD-LH2, and PucE-LH2. The structures of all four purified LH2 complexes were determined by cryogenic electron microscopy (cryo-EM) at resolutions ranging from 2.7 to 3.6 A. Uniquely, each of these complexes contains a hitherto unknown polypeptide, gamma, that forms an extended undulating ribbon that lies in the plane of the membrane and that encloses six of the nine LH2 alphabeta-subunits. The gamma-subunit, which is located near to the cytoplasmic side of the complex, breaks the C9 symmetry of the LH2 complex and binds six extra bacteriochlorophylls (BChls) that enhance the 800-nm absorption of each complex. The structures show that all four complexes have two complete rings of BChls, conferring absorption bands centered at 800 and 850 nm on the PucA-LH2, PucB-LH2, and PucE-LH2 complexes, but, unusually, the PucD-LH2 antenna has only a single strong near-infared (NIR) absorption peak at 803 nm. Comparison of the cryo-EM structures of these LH2 complexes reveals altered patterns of hydrogen bonds between LH2 alphabeta-side chains and the bacteriochlorin rings, further emphasizing the major role that H bonds play in spectral tuning of bacterial antenna complexes.

Cryo-EM structures of light-harvesting 2 complexes from Rhodopseudomonas palustris reveal the molecular origin of absorption tuning.,Qian P, Nguyen-Phan CT, Gardiner AT, Croll TI, Roszak AW, Southall J, Jackson PJ, Vasilev C, Castro-Hartmann P, Sader K, Hunter CN, Cogdell RJ Proc Natl Acad Sci U S A. 2022 Oct 25;119(43):e2210109119. doi: , 10.1073/pnas.2210109119. Epub 2022 Oct 17. PMID:36251992<ref>PMID:36251992</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7zcu" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Rhodopseudomonas palustris ATCC 17001]]
[[Category: Cogdell RJ]]
[[Category: Qian P]]