View source for 4wxh


==Carminomycin-4-O-methyltransferase (DnrK) variant (298Ser insert) in complex with S-adenosyl-L-homocysteine (SAH) and aclacinomycin T==
<StructureSection load='4wxh' size='340' side='right'caption='[[4wxh]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4wxh]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_peucetius Streptomyces peucetius]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4WXH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4WXH 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=3VL:METHYL+(1R,2R,4S)-2-ETHYL-2,5,7-TRIHYDROXY-6,11-DIOXO-4-{[2,3,6-TRIDEOXY-3-(DIMETHYLAMINO)-ALPHA-L-LYXO-HEXOPYRANOSYL]OXY}-1,2,3,4,6,11-HEXAHYDROTETRACENE-1-CARBOXYLATE'>3VL</scene>, <scene name='pdbligand=DTU:(2R,3S)-1,4-DIMERCAPTOBUTANE-2,3-DIOL'>DTU</scene>, <scene name='pdbligand=SAH:S-ADENOSYL-L-HOMOCYSTEINE'>SAH</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4wxh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4wxh OCA], [https://pdbe.org/4wxh PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4wxh RCSB], [https://www.ebi.ac.uk/pdbsum/4wxh PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4wxh ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DNRK_STRPE DNRK_STRPE] Involved in the biosynthesis of the anthracyclines carminomycin and daunorubicin (daunomycin) which are aromatic polyketide antibiotics that exhibit high cytotoxicity and are widely applied in the chemotherapy of a variety of cancers. In vivo, catalyzes the transfer of a methyl group from S-adenosyl-L-methionine to the 4-O-position of carminomycin to form daunorubicin. In vitro, it also methylates the anthracyclines rhodomycin D (10-carbomethoxy-13-deoxycarminomycin) and 13-deoxy-carminomycin at the 4-hydroxyl position. It is quite specific with respect to the length of the carbohydrate chain at the C7 position, but it can accept substrates with bulky substituent at C10 position.<ref>PMID:15273252</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Bacterial secondary metabolic pathways are responsible for the biosynthesis of thousands of bioactive natural products. Many enzymes residing in these pathways have evolved to catalyze unusual chemical transformations, which is facilitated by an evolutionary pressure promoting chemical diversity. Such divergent enzyme evolution has been observed in S-adenosyl-l-methionine (SAM)-dependent methyltransferases involved in the biosynthesis of anthracycline anticancer antibiotics; whereas DnrK from the daunorubicin pathway is a canonical 4-O-methyltransferase, the closely related RdmB (52% sequence identity) from the rhodomycin pathways is an atypical 10-hydroxylase that requires SAM, a thiol reducing agent, and molecular oxygen for activity. Here, we have used extensive chimeragenesis to gain insight into the functional differentiation of RdmB and show that insertion of a single serine residue to DnrK is sufficient for introduction of the monooxygenation activity. The crystal structure of DnrK-Ser in complex with aclacinomycin T and S-adenosyl-l-homocysteine refined to 1.9-A resolution revealed that the inserted serine S297 resides in an alpha-helical segment adjacent to the substrate, but in a manner where the side chain points away from the active site. Further experimental work indicated that the shift in activity is mediated by rotation of a preceding phenylalanine F296 toward the active site, which blocks a channel to the surface of the protein that is present in native DnrK. The channel is also closed in RdmB and may be important for monooxygenation in a solvent-free environment. Finally, we postulate that the hydroxylation ability of RdmB originates from a previously undetected 10-decarboxylation activity of DnrK.

Divergent evolution of an atypical S-adenosyl-l-methionine-dependent monooxygenase involved in anthracycline biosynthesis.,Grocholski T, Dinis P, Niiranen L, Niemi J, Metsa-Ketela M Proc Natl Acad Sci U S A. 2015 Jul 27. pii: 201501765. PMID:26216966<ref>PMID:26216966</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4wxh" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptomyces peucetius]]
[[Category: Metsa-Ketela M]]
[[Category: Niiranen L]]