Reaction participants Show >> << Hide
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Namehelp_outline
guanosine2535 in 23S rRNA
Identifier
RHEA-COMP:10337
Reactive part
help_outline
- Name help_outline GMP residue Identifier CHEBI:74269 Charge -1 Formula C10H11N5O7P Positionhelp_outline 2535 SMILEShelp_outline C1(=O)NC(=NC2=C1N=CN2[C@@H]3O[C@H](COP(=O)(*)[O-])[C@@H](O*)[C@H]3O)N 2D coordinates Mol file for the small molecule Search links Involved in 42 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline S-adenosyl-L-methionine Identifier CHEBI:59789 Charge 1 Formula C15H23N6O5S InChIKeyhelp_outline MEFKEPWMEQBLKI-AIRLBKTGSA-O SMILEShelp_outline C[S+](CC[C@H]([NH3+])C([O-])=O)C[C@H]1O[C@H]([C@H](O)[C@@H]1O)n1cnc2c(N)ncnc12 2D coordinates Mol file for the small molecule Search links Involved in 904 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
N1-methylguanosine2535 in 23S rRNA
Identifier
RHEA-COMP:10338
Reactive part
help_outline
- Name help_outline N1-methylguanosine residue Identifier CHEBI:73542 Charge -1 Formula C11H13N5O7P Positionhelp_outline 2535 SMILEShelp_outline O=C1N(C(=NC2=C1N=CN2[C@@H]3O[C@H](COP(=O)(*)[O-])[C@@H](O*)[C@H]3O)N)C 2D coordinates Mol file for the small molecule Search links Involved in 6 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline S-adenosyl-L-homocysteine Identifier CHEBI:57856 Charge 0 Formula C14H20N6O5S InChIKeyhelp_outline ZJUKTBDSGOFHSH-WFMPWKQPSA-N SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](CSCC[C@H]([NH3+])C([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 827 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,521 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:43096 | RHEA:43097 | RHEA:43098 | RHEA:43099 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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EC numbers help_outline | ||||
MetaCyc help_outline |
Publications
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Crystal structure of the avilamycin resistance-conferring methyltransferase AviRa from Streptomyces viridochromogenes.
Mosbacher T.G., Bechthold A., Schulz G.E.
The emergence of antibiotic-resistant bacterial strains is a widespread problem in contemporary medical practice and drug design. It is therefore important to elucidate the underlying mechanism in each case. The methyltransferase AviRa from Streptomyces viridochromogenes mediates resistance to the ... >> More
The emergence of antibiotic-resistant bacterial strains is a widespread problem in contemporary medical practice and drug design. It is therefore important to elucidate the underlying mechanism in each case. The methyltransferase AviRa from Streptomyces viridochromogenes mediates resistance to the antibiotic avilamycin, which is closely related to evernimicin, an oligosaccharide antibiotic that has been used in medical studies. The structure of AviRa was determined by X-ray diffraction at 1.5A resolution. Phases were obtained from one selenomethionine residue introduced by site-directed mutagenesis. The chain-fold is similar to that of most methyltransferases, although AviRa contains two additional helices as a specific feature. A putative-binding site for the cofactor S-adenosyl-L-methionine was derived from homologous structures. It agrees with the conserved pattern of interacting amino acid residues. AviRa methylates a specific guanine base within the peptidyltransferase loop of the 23S ribosomal RNA. Guided by the target, the enzyme was docked to the cognate ribosomal surface, where it fit well into a deep cleft without contacting any ribosomal protein. The two additional alpha-helices of AviRa filled a depression in the surface. Since the transferred methyl group of the cofactor is in a pocket beneath the enzyme surface, the targeted guanine base has to flip out for methylation. << Less
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The avilamycin resistance determinants AviRa and AviRb methylate 23S rRNA at the guanosine 2535 base and the uridine 2479 ribose.
Treede I., Jakobsen L., Kirpekar F., Vester B., Weitnauer G., Bechthold A., Douthwaite S.
Avilamycin is an orthosomycin antibiotic that has shown considerable potential for clinical use, although it is presently used as a growth promoter in animal feed. Avilamycin inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. The ribosomes of the producer strain, Strepto ... >> More
Avilamycin is an orthosomycin antibiotic that has shown considerable potential for clinical use, although it is presently used as a growth promoter in animal feed. Avilamycin inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. The ribosomes of the producer strain, Streptomyces viridochromogenes Tü57, are protected from the drug by the action of three resistance factors located in the avilamycin biosynthetic gene cluster. Two of the resistance factors, aviRa and aviRb, encode rRNA methyltransferases that specifically target 23S rRNA. Recombinant AviRa and AviRb proteins retain their activity after purification, and both specifically methylate in vitro transcripts of 23S rRNA domain V. Reverse transcriptase primer extension indicated that AviRa is an N-methyltransferase that targets G2535 within helix 91 of the rRNA, whereas AviRb modified the 2'-O-ribose position of nucleotide U2479 within helix 89. MALDI mass spectrometry confirmed the exact positions of each of these modifications, and additionally established that a single methyl group is added at each nucleotide. Neither of these two nucleotides have previously been described as a target for enzymatic methylation. Molecular models of the 50S subunit crystal structure show that the N-1 of the G2535 base and the 2'-hydroxyl of U2479 are separated by approximately 10 A, a distance that can be spanned by avilamycin. In addition to defining new resistance mechanisms, these data refine our understanding of the probable ribosome contacts made by orthosomycins and of how these antibiotics inhibit protein synthesis. << Less
Mol. Microbiol. 49:309-318(2003) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.