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| | == Structural highlights == | | == Structural highlights == |
| | <table><tr><td colspan='2'>[[3bw7]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Zea_mays Zea mays]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3BW7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3BW7 FirstGlance]. <br> | | <table><tr><td colspan='2'>[[3bw7]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Zea_mays Zea mays]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3BW7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3BW7 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=301:N6-(PENTA-2,3-DIENYL)ADENINE'>301</scene>, <scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.95Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[2qkn|2qkn]], [[2qpm|2qpm]]</div></td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=301:N6-(PENTA-2,3-DIENYL)ADENINE'>301</scene>, <scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">CKX1, ZmCKO1 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=4577 Zea mays])</td></tr>
| + | |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Cytokinin_dehydrogenase Cytokinin dehydrogenase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.5.99.12 1.5.99.12] </span></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=3bw7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3bw7 OCA], [https://pdbe.org/3bw7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3bw7 RCSB], [https://www.ebi.ac.uk/pdbsum/3bw7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3bw7 ProSAT]</span></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=3bw7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3bw7 OCA], [https://pdbe.org/3bw7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3bw7 RCSB], [https://www.ebi.ac.uk/pdbsum/3bw7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3bw7 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[https://www.uniprot.org/uniprot/CKX1_MAIZE CKX1_MAIZE]] Catalyzes the oxidation of cytokinins, a family of N(6)-substituted adenine derivatives that are plant hormones, where the substituent is an isopentenyl group. Cleaves zeatin, isopentenyladenine, isopentenyladenosine, zeatin riboside and cis-zeatin, but not dihydrozeatin, kinetin and benzylaminopurine.
| + | [https://www.uniprot.org/uniprot/CKX1_MAIZE CKX1_MAIZE] Catalyzes the oxidation of cytokinins, a family of N(6)-substituted adenine derivatives that are plant hormones, where the substituent is an isopentenyl group. Cleaves zeatin, isopentenyladenine, isopentenyladenosine, zeatin riboside and cis-zeatin, but not dihydrozeatin, kinetin and benzylaminopurine. |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Cytokinin dehydrogenase]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| | [[Category: Zea mays]] | | [[Category: Zea mays]] |
| - | [[Category: Briozzo, P]] | + | [[Category: Briozzo P]] |
| - | [[Category: Kopecny, D]] | + | [[Category: Kopecny D]] |
| - | [[Category: Cytokinin oxidase/dehydrogenase]]
| + | |
| - | [[Category: Fad]]
| + | |
| - | [[Category: Ha-1 inhibitor]]
| + | |
| - | [[Category: Oxidoreductase]]
| + | |
| Structural highlights
Function
CKX1_MAIZE Catalyzes the oxidation of cytokinins, a family of N(6)-substituted adenine derivatives that are plant hormones, where the substituent is an isopentenyl group. Cleaves zeatin, isopentenyladenine, isopentenyladenosine, zeatin riboside and cis-zeatin, but not dihydrozeatin, kinetin and benzylaminopurine.
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 PubMed
Cytokinin oxidases/dehydrogenases (CKOs) mediate catabolic regulation of cytokinin levels in plants. Several substrate analogs containing an unsaturated side chain were studied for their possible inhibitory effect on maize CKO (ZmCKO1) by use of various bioanalytical methods. Two allenic derivatives, N(6)-(buta-2,3-dienyl)adenine (HA-8) and N(6)-(penta-2,3-dienyl)adenine (HA-1), were identified as strong mechanism-based inhibitors of the enzyme. Despite exhaustive dialysis, the enzyme remained inhibited. Conversely, substrate analogs with a triple bond in the side chain were much weaker inactivators. The crystal structures of recombinant ZmCKO1 complexed with HA-1 or HA-8 were solved to 1.95 A resolution. Together with Raman spectra of the inactivated enzyme, it was revealed that reactive imine intermediates generated by oxidation of the allenic inhibitors covalently bind to the flavin adenine dinucleotide (FAD) cofactor. The binding occurs at the C4a atom of the isoalloxazine ring of FAD, the planarity of which is consequently disrupted. All the compounds under study were also analyzed for binding to the Arabidopsis cytokinin receptors AHK3 and AHK4 in a bacterial receptor assay and for cytokinin activity in the Amaranthus bioassay. HA-1 and HA-8 were found to be good receptor ligands with a significant cytokinin activity. Nevertheless, due to their ability to inactivate CKO in the desired time intervals or developmental stages, they both represent attractive compounds for physiological studies, as the inhibition mechanism of HA-1 and HA-8 is mainly FAD dependent.
Mechanism-based inhibitors of cytokinin oxidase/dehydrogenase attack FAD cofactor.,Kopecny D, Sebela M, Briozzo P, Spichal L, Houba-Herin N, Masek V, Joly N, Madzak C, Anzenbacher P, Laloue M J Mol Biol. 2008 Jul 25;380(5):886-99. Epub 2008 May 24. PMID:18571199[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kopecny D, Sebela M, Briozzo P, Spichal L, Houba-Herin N, Masek V, Joly N, Madzak C, Anzenbacher P, Laloue M. Mechanism-based inhibitors of cytokinin oxidase/dehydrogenase attack FAD cofactor. J Mol Biol. 2008 Jul 25;380(5):886-99. Epub 2008 May 24. PMID:18571199 doi:10.1016/j.jmb.2008.05.044
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