4b2n: Difference between revisions
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==Latex Oxygenase RoxA== | |||
=== | <StructureSection load='4b2n' size='340' side='right' caption='[[4b2n]], [[Resolution|resolution]] 1.80Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4b2n]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Xanthomonas_sp. Xanthomonas sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4B2N OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4B2N FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EPE:4-(2-HYDROXYETHYL)-1-PIPERAZINE+ETHANESULFONIC+ACID'>EPE</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=OXY:OXYGEN+MOLECULE'>OXY</scene></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=4b2n FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4b2n OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4b2n RCSB], [http://www.ebi.ac.uk/pdbsum/4b2n PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Rubber oxygenase A (RoxA) is one of only two known enzymes able to catalyze the oxidative cleavage of latex for biodegradation. RoxA acts as a processive dioxygenase to yield the predominant product 12-oxo-4,8-dimethyl-trideca-4,8-diene-1-al (ODTD), a tri-isoprene unit. Here we present a structural analysis of RoxA from Xanthomonas sp. strain 35Y at a resolution of 1.8 A. The enzyme is a 75-kDa diheme c-type cytochrome with an unusually low degree of secondary structure. Analysis of the heme group arrangement and peptide chain topology of RoxA confirmed a distant kinship with diheme peroxidases of the CcpA family, but the proteins are functionally distinct, and the extracellular RoxA has evolved to have twice the molecular mass by successively accumulating extensions of peripheral loops. RoxA incorporates both oxygen atoms of its cosubstrate dioxygen into the rubber cleavage product ODTD, and we show that RoxA is isolated with O2 stably bound to the active site heme iron. Activation and cleavage of O2 require binding of polyisoprene, and thus the substrate needs to use hydrophobic access channels to reach the deeply buried active site of RoxA. The location and nature of these channels support a processive mechanism of latex cleavage. | |||
Structure of the processive rubber oxygenase RoxA from Xanthomonas sp.,Seidel J, Schmitt G, Hoffmann M, Jendrossek D, Einsle O Proc Natl Acad Sci U S A. 2013 Aug 20;110(34):13833-8. doi:, 10.1073/pnas.1305560110. Epub 2013 Aug 6. PMID:23922395<ref>PMID:23922395</ref> | |||
== | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
[[Category: Xanthomonas sp | == References == | ||
[[Category: Einsle, O | <references/> | ||
[[Category: Hoffmann, M | __TOC__ | ||
[[Category: Jendrossek, D | </StructureSection> | ||
[[Category: Schmitt, G | [[Category: Xanthomonas sp]] | ||
[[Category: Seidel, J | [[Category: Einsle, O]] | ||
[[Category: Hoffmann, M]] | |||
[[Category: Jendrossek, D]] | |||
[[Category: Schmitt, G]] | |||
[[Category: Seidel, J]] | |||
[[Category: Cytochrome]] | [[Category: Cytochrome]] | ||
[[Category: Dioxygenase]] | [[Category: Dioxygenase]] | ||
[[Category: Electron transport]] | [[Category: Electron transport]] | ||
[[Category: Rubber oxygenase]] | [[Category: Rubber oxygenase]] | ||
Revision as of 12:26, 21 December 2014
Latex Oxygenase RoxALatex Oxygenase RoxA
Structural highlights
Publication Abstract from PubMedRubber oxygenase A (RoxA) is one of only two known enzymes able to catalyze the oxidative cleavage of latex for biodegradation. RoxA acts as a processive dioxygenase to yield the predominant product 12-oxo-4,8-dimethyl-trideca-4,8-diene-1-al (ODTD), a tri-isoprene unit. Here we present a structural analysis of RoxA from Xanthomonas sp. strain 35Y at a resolution of 1.8 A. The enzyme is a 75-kDa diheme c-type cytochrome with an unusually low degree of secondary structure. Analysis of the heme group arrangement and peptide chain topology of RoxA confirmed a distant kinship with diheme peroxidases of the CcpA family, but the proteins are functionally distinct, and the extracellular RoxA has evolved to have twice the molecular mass by successively accumulating extensions of peripheral loops. RoxA incorporates both oxygen atoms of its cosubstrate dioxygen into the rubber cleavage product ODTD, and we show that RoxA is isolated with O2 stably bound to the active site heme iron. Activation and cleavage of O2 require binding of polyisoprene, and thus the substrate needs to use hydrophobic access channels to reach the deeply buried active site of RoxA. The location and nature of these channels support a processive mechanism of latex cleavage. Structure of the processive rubber oxygenase RoxA from Xanthomonas sp.,Seidel J, Schmitt G, Hoffmann M, Jendrossek D, Einsle O Proc Natl Acad Sci U S A. 2013 Aug 20;110(34):13833-8. doi:, 10.1073/pnas.1305560110. Epub 2013 Aug 6. PMID:23922395[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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