4k9j: Difference between revisions
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==Structure of Re(CO)3(4,7-dimethyl-phen)(Thr126His)(Lys122Trp)(His83Glu)(Trp48Phe)(Tyr72Phe)(Tyr108Phe)AzCu(II), a Rhenium modified Azurin mutant== | |||
<StructureSection load='4k9j' size='340' side='right' caption='[[4k9j]], [[Resolution|resolution]] 1.70Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4k9j]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Pseae Pseae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4K9J OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4K9J FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene>, <scene name='pdbligand=REQ:(1,10+PHENANTHROLINE)-(TRI-CARBON+MONOXIDE)+RHENIUM+(I)'>REQ</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4azu|4azu]]</td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">azu, PA4922 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=208964 PSEAE])</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=4k9j FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4k9j OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4k9j RCSB], [http://www.ebi.ac.uk/pdbsum/4k9j PDBsum]</span></td></tr> | |||
</table> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/AZUR_PSEAE AZUR_PSEAE]] Transfers electrons from cytochrome c551 to cytochrome oxidase. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Re126W122CuI Pseudomonas aeruginosa azurin incorporates three redox sites, ReI(CO)3(4,7-dimethyl-1,10-phenanthroline) covalently bound at H126, the W122 indole side chain, and CuI, which are well separated in the protein fold: Re-W122(indole) = 13.1 A; dmp-W122(indole) = 10.0 A, Re-Cu = 25.6 A. In view of the long intramolecular Re-Cu distance, it is surprising that CuI is oxidized in less than 50 ns after near-UV excitation of the Re chromophore. Back electron transfer (BET) regenerating CuI and ground-state ReI takes much longer (220 ns and 6 us). We show that these ET reactions occur in protein dimers, (Re126W122CuI)2, which are in equilibrium with unreactive monomers. In support of this interpretation, ET yields and kinetics are concentration-dependent and solution mass spectrometry (LILBID-MS) confirms the presence of a broad oligomer distribution with prevalent monomers and dimers; in the crystal structure, two Re126W122CuII molecules are oriented in such a way that the redox cofactors Re(dmp) and W122-indole belonging to different monomers are located at a protein-protein interface (//), where the intermolecular ET-relevant distances (Re-W122(indole) = 6.9 A, dmp-W122(indole) = 3.5 A, and Re-Cu = 14.0 A) are much shorter than intramolecular ones. We propose that forward ET is accelerated by intermolecular electron hopping through a surface tryptophan: *Re//<-W122<-CuI; our kinetics analysis indicates that an equilibrium (K = 0.8-0.9) between *Re and charge-separated Re(dmp*-)(W122*+), which is established in a few ns, stores part of the excitation energy. The second ET step, intramolecular CuI oxidation, CuI->W122*+, occurs in 30 ns. The system is well coupled for forward ET but not for ReI(dmp*-)->CuII BET. Our work on interfacial electron hopping in (Re126W122CuI)2 sheds new light on redox-unit placements required for functional long-range charge separation in protein complexes. | |||
Tryptophan-accelerated electron flow across a protein-protein interface.,Takematsu K, Williamson H, Blanco-Rodriguez AM, Sokolova L, Nikolovski P, Kaiser JT, Towrie M, Clark IP, Vlcek A, Winkler JR, Gray HB J Am Chem Soc. 2013 Sep 13. PMID:24032375<ref>PMID:24032375</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== | ==See Also== | ||
*[[Azurin|Azurin]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Pseae]] | [[Category: Pseae]] | ||
[[Category: Blanco-Rodriguez, A M | [[Category: Blanco-Rodriguez, A M]] | ||
[[Category: Clark, I P | [[Category: Clark, I P]] | ||
[[Category: Gray, H B | [[Category: Gray, H B]] | ||
[[Category: Jr, A Vlcek | [[Category: Jr, A Vlcek]] | ||
[[Category: Kaiser, J T | [[Category: Kaiser, J T]] | ||
[[Category: Nikolovski, P | [[Category: Nikolovski, P]] | ||
[[Category: Sokolova, L | [[Category: Sokolova, L]] | ||
[[Category: Takematsu, K | [[Category: Takematsu, K]] | ||
[[Category: Towrie, M | [[Category: Towrie, M]] | ||
[[Category: Williamson, H R | [[Category: Williamson, H R]] | ||
[[Category: Winkler, J R | [[Category: Winkler, J R]] | ||
[[Category: Electron transport]] | [[Category: Electron transport]] | ||
[[Category: Rhenium]] | [[Category: Rhenium]] | ||
