2hxc: Difference between revisions
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< | ==Crystal structure of the benzylamine complex of aromatic amine dehydrogenase in N-semiquinone form== | ||
<StructureSection load='2hxc' size='340' side='right'caption='[[2hxc]], [[Resolution|resolution]] 1.45Å' scene=''> | |||
You may | == Structural highlights == | ||
<table><tr><td colspan='2'>[[2hxc]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Alcaligenes_faecalis Alcaligenes faecalis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HXC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2HXC 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]] 1.45Å</td></tr> | |||
-- | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ABN:BENZYLAMINE'>ABN</scene>, <scene name='pdbligand=TTQ:6-AMINO-7-HYDROXY-L-TRYPTOPHAN'>TTQ</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=2hxc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hxc OCA], [https://pdbe.org/2hxc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2hxc RCSB], [https://www.ebi.ac.uk/pdbsum/2hxc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2hxc ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/AAUA_ALCFA AAUA_ALCFA] Oxidizes primary aromatic amines and, more slowly, some long-chain aliphatic amines, but not methylamine or ethylamine. Uses azurin as an electron acceptor to transfer electrons from the reduced tryptophylquinone cofactor.<ref>PMID:11495996</ref> <ref>PMID:16279953</ref> <ref>PMID:8188594</ref> <ref>PMID:7876189</ref> <ref>PMID:17087503</ref> <ref>PMID:17005560</ref> <ref>PMID:16614214</ref> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/hx/2hxc_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2hxc ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The quinoprotein aromatic amine dehydrogenase (AADH) uses a covalently bound tryptophan tryptophylquinone (TTQ) cofactor to oxidatively deaminate primary aromatic amines. Recent crystal structures have provided insight into the reductive half-reaction. In contrast, no atomic details are available for the oxidative half-reaction. The TTQ O7 hydroxyl group is protonated during reduction, but it is unclear how this proton can be removed during the oxidative half-reaction. Furthermore, compared with the electron transfer from the N-quinol form, electron transfer from the non-physiological O-quinol form to azurin is significantly slower. Here we report crystal structures of the O-quinol, N-quinol, and N-semiquinone forms of AADH. A comparison of oxidized and substrate reduced AADH species reveals changes in the TTQ-containing subunit, extending from residues in the immediate vicinity of the N-quinol to the putative azurin docking site, suggesting a mechanism whereby TTQ redox state influences interprotein electron transfer. In contrast, chemical reduction of the TTQ center has no significant effect on protein conformation. Furthermore, structural reorganization upon substrate reduction places a water molecule near TTQ O7 where it can act as proton acceptor. The structure of the N-semiquinone, however, is essentially similar to oxidized AADH. Surprisingly, in the presence of substrate a covalent N-semiquinone substrate adduct is observed. To our knowledge this is the first detailed insight into a complex, branching mechanism of quinone oxidation where significant structural reorganization upon reduction of the quinone center directly influences formation of the electron transfer complex and nature of the electron transfer process. | |||
Atomic level insight into the oxidative half-reaction of aromatic amine dehydrogenase.,Roujeinikova A, Scrutton NS, Leys D J Biol Chem. 2006 Dec 29;281(52):40264-72. Epub 2006 Sep 27. PMID:17005560<ref>PMID:17005560</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2hxc" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Aromatic amine dehydrogenase 3D structures|Aromatic amine dehydrogenase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | |||
== | |||
< | |||
[[Category: Alcaligenes faecalis]] | [[Category: Alcaligenes faecalis]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Leys | [[Category: Leys D]] | ||
[[Category: Roujeinikova | [[Category: Roujeinikova A]] | ||
Latest revision as of 04:02, 21 November 2024
Crystal structure of the benzylamine complex of aromatic amine dehydrogenase in N-semiquinone formCrystal structure of the benzylamine complex of aromatic amine dehydrogenase in N-semiquinone form
Structural highlights
FunctionAAUA_ALCFA Oxidizes primary aromatic amines and, more slowly, some long-chain aliphatic amines, but not methylamine or ethylamine. Uses azurin as an electron acceptor to transfer electrons from the reduced tryptophylquinone cofactor.[1] [2] [3] [4] [5] [6] [7] 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 PubMedThe quinoprotein aromatic amine dehydrogenase (AADH) uses a covalently bound tryptophan tryptophylquinone (TTQ) cofactor to oxidatively deaminate primary aromatic amines. Recent crystal structures have provided insight into the reductive half-reaction. In contrast, no atomic details are available for the oxidative half-reaction. The TTQ O7 hydroxyl group is protonated during reduction, but it is unclear how this proton can be removed during the oxidative half-reaction. Furthermore, compared with the electron transfer from the N-quinol form, electron transfer from the non-physiological O-quinol form to azurin is significantly slower. Here we report crystal structures of the O-quinol, N-quinol, and N-semiquinone forms of AADH. A comparison of oxidized and substrate reduced AADH species reveals changes in the TTQ-containing subunit, extending from residues in the immediate vicinity of the N-quinol to the putative azurin docking site, suggesting a mechanism whereby TTQ redox state influences interprotein electron transfer. In contrast, chemical reduction of the TTQ center has no significant effect on protein conformation. Furthermore, structural reorganization upon substrate reduction places a water molecule near TTQ O7 where it can act as proton acceptor. The structure of the N-semiquinone, however, is essentially similar to oxidized AADH. Surprisingly, in the presence of substrate a covalent N-semiquinone substrate adduct is observed. To our knowledge this is the first detailed insight into a complex, branching mechanism of quinone oxidation where significant structural reorganization upon reduction of the quinone center directly influences formation of the electron transfer complex and nature of the electron transfer process. Atomic level insight into the oxidative half-reaction of aromatic amine dehydrogenase.,Roujeinikova A, Scrutton NS, Leys D J Biol Chem. 2006 Dec 29;281(52):40264-72. Epub 2006 Sep 27. PMID:17005560[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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