4iwn: Difference between revisions
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==Crystal structure of a putative methyltransferase CmoA in complex with a novel SAM derivative== | |||
<StructureSection load='4iwn' size='340' side='right' caption='[[4iwn]], [[Resolution|resolution]] 1.73Å' scene=''> | |||
{ | == Structural highlights == | ||
<table><tr><td colspan='2'>[[4iwn]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Streptomyces_aureorectus Streptomyces aureorectus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4IWN OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4IWN FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GEK:(2S)-4-[{[(2S,3S,4R,5R)-5-(6-AMINO-9H-PURIN-9-YL)-3,4-DIHYDROXYTETRAHYDROFURAN-2-YL]METHYL}(CARBOXYLATOMETHYL)SULFONIO]-2-AMMONIOBUTANOATE'>GEK</scene>, <scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</scene></td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">cmoA, yecO, b1870, JW1859 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=285571 Streptomyces aureorectus])</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=4iwn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4iwn OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4iwn RCSB], [http://www.ebi.ac.uk/pdbsum/4iwn PDBsum]</span></td></tr> | |||
</table> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/CMOA_ECOLI CMOA_ECOLI]] Catalyzes the conversion of 5-methoxyuridine (mo5U) to uridine-5-oxyacetic acid (cmo5U) at position 34 in tRNA. May also participate in the methylation of uridine-5-oxyacetic acid (cmo5U) to uridine-5-oxyacetic acid methyl ester (mcmo5U) (By similarity). | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Uridine at position 34 of bacterial transfer RNAs is commonly modified to uridine-5-oxyacetic acid (cmo(5)U) to increase the decoding capacity. The protein CmoA is involved in the formation of cmo(5)U and was annotated as an S-adenosyl-L-methionine-dependent (SAM-dependent) methyltransferase on the basis of its sequence homology to other SAM-containing enzymes. However, both the crystal structure of Escherichia coli CmoA at 1.73 A resolution and mass spectrometry demonstrate that it contains a novel cofactor, S-adenosyl-S-carboxymethyl-L-homocysteine (SCM-SAH), in which the donor methyl group is substituted by a carboxymethyl group. The carboxyl moiety forms a salt-bridge interaction with Arg199 that is conserved in a large group of CmoA-related proteins but is not conserved in other SAM-containing enzymes. This raises the possibility that a number of enzymes that have previously been annotated as SAM-dependent are in fact SCM-SAH-dependent. Indeed, inspection of electron density for one such enzyme with known X-ray structure, PDB entry 1im8, suggests that the active site contains SCM-SAH and not SAM. | |||
S-Adenosyl-S-carboxymethyl-L-homocysteine: a novel cofactor found in the putative tRNA-modifying enzyme CmoA.,Byrne RT, Whelan F, Aller P, Bird LE, Dowle A, Lobley CM, Reddivari Y, Nettleship JE, Owens RJ, Antson AA, Waterman DG Acta Crystallogr D Biol Crystallogr. 2013 Jun;69(Pt 6):1090-8. doi:, 10.1107/S0907444913004939. Epub 2013 May 15. PMID:23695253<ref>PMID:23695253</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== | ==See Also== | ||
*[[TRNA methyltransferase|TRNA methyltransferase]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Streptomyces aureorectus]] | [[Category: Streptomyces aureorectus]] | ||
[[Category: Aller, P | [[Category: Aller, P]] | ||
[[Category: Antson, A A | [[Category: Antson, A A]] | ||
[[Category: Byrne, R T | [[Category: Byrne, R T]] | ||
[[Category: Lobley, C M | [[Category: Lobley, C M]] | ||
[[Category: Waterman, D G | [[Category: Waterman, D G]] | ||
[[Category: Putative trna modification enzyme]] | [[Category: Putative trna modification enzyme]] | ||
[[Category: Scm-sah]] | [[Category: Scm-sah]] | ||
[[Category: Transferase]] | [[Category: Transferase]] | ||
Revision as of 02:34, 25 December 2014
Crystal structure of a putative methyltransferase CmoA in complex with a novel SAM derivative
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