23S rRNA (adenine2085-N6)-dimethyltransferase
This protein produces a dimethylation of the adenine residue at position 2085 in 23S rRNA, resulting in reduced affinity between ribosomes and macrolide-lincosamide-streptogramin B antibiotics.
Reference Protein and Structure
- Sequence
-
P13956
(2.1.1.184)
(Sequence Homologues)
(PDB Homologues)
- Biological species
-
Bacillus subtilis (Bacteria)
- PDB
-
1qam
- THE STRUCTURE OF THE RRNA METHYLTRANSFERASE ERMC': IMPLICATIONS FOR THE REACTION MECHANISM
(2.2 Å)
- Catalytic CATH Domains
-
3.40.50.150
(see all for 1qam)
Enzyme Reaction (EC:2.1.1.184)
+
→
+
+
Alternative enzyme names: ErmC' methyltransferase, ErmC methylase, ErmC 23S rRNA methyltransferase, rRNA:m(6)A methyltransferase ErmC', ErmC', rRNA methyltransferase ErmC',
Enzyme Mechanism
Introduction
It is thought that this enzyme catalyses the direct methyl transfer from the substrate SAM to the RNA substrate.
Catalytic Residues Roles
| UniProt | PDB* (1qam) | ||
| Tyr104, Phe163, Gly38 (main-C), Glu59, Asn101 | Tyr104A, Phe163A, Gly38A (main-C), Glu59A, Asn101A | The catalytic residues in this enzyme are all thought to be involved in the activation of the substrates and stabilisation of the reactive intermediates and transition states formed. Mutagenesis has shown that only Y104 is critical, which is responsible for the activation and stabilisation of the substrate base. | activator, electrostatic stabiliser |
*PDB label guide - RESx(y)B(C) - RES: Residue Name; x: Residue ID in PDB file;
y: Residue ID in PDB sequence if different from PDB file; B: PDB Chain;
C: Biological Assembly Chain if different from PDB. If label is "Not Found" it means this residue is not found in the reference PDB.
Chemical Components
References
- Maravić G et al. (2003), J Mol Biol, 332, 99-109. Mutational analysis defines the roles of conserved amino acid residues in the predicted catalytic pocket of the rRNA:m6A methyltransferase ErmC'. PMID:12946350.
- Maravić G et al. (2003), Nucleic Acids Res, 31, 4941-4949. Alanine-scanning mutagenesis of the predicted rRNA-binding domain of ErmC' redefines the substrate-binding site and suggests a model for protein-RNA interactions. PMID:12907737.
- Schluckebier G et al. (1999), J Mol Biol, 289, 277-291. The 2.2 Å structure of the rRNA methyltransferase ErmC′ and its complexes with cofactor and cofactor analogs: implications for the reaction mechanism. DOI:10.1006/jmbi.1999.2788. PMID:10366505.
- Bussiere DE et al. (1998), Biochemistry, 37, 7103-7112. Crystal Structure of ErmC‘, an rRNA Methyltransferase Which Mediates Antibiotic Resistance in Bacteria‡. DOI:10.1021/bi973113c. PMID:9585521.
Catalytic Residues Roles
| Residue | Roles |
|---|---|
| Gly38A (main-C) | activator |
| Glu59A | activator |
| Asn101A | activator |
| Tyr104A | activator |
| Phe163A | activator |
| Gly38A (main-C) | electrostatic stabiliser |
| Glu59A | electrostatic stabiliser |
| Asn101A | electrostatic stabiliser |
| Tyr104A | electrostatic stabiliser |
| Phe163A | electrostatic stabiliser |