TY  - JOUR
AU  - Savić, Miloje
AU  - Ilić-Tomić, Tatjana
AU  - Macmaster, Rachel
AU  - Vasiljević, Branka
AU  - Conn, Graeme L.
PY  - 2008
UR  - https://imagine.imgge.bg.ac.rs/handle/123456789/328
AB  - The 16S rRNA methyltransferase Sgm from "Micromonospora zionensis" confers resistance to aminoglycoside antibiotics by specific modification of the 30S ribosomal A site. Sgm is a member of the FmrO family, distant relatives of the S-adenosyl-L-methionine (SAM)-dependent RNA subfamily of methyltransferase enzymes. Using amino acid conservation across the FmrO family, seven putative key amino acids were selected for mutation to assess their role in forming the SAM cofactor binding pocket or in methyl group transfer. Each mutated residue was found to be essential for Sgm function, as no modified protein could effectively support bacterial growth in liquid media containing gentamicin or methylate 30S subunits in vitro. Using isothermal titration calorimetry, Sgm was found to bind SAM with a K-D (binding constant) of 17.6 mu M, and comparable values were obtained for one functional mutant (N179A) and four proteins modified at amino acids predicted to be involved in catalysis in methyl group transfer. In contrast, none of the G135, D156, or D182 Sgm mutants bound the cofactor, confirming their role in creating the SAM binding pocket. These results represent the first functional characterization of any FmrO methyltransferase and may provide a basis for a further structurefunction analysis of these aminoglycoside resistance determinants.
PB  - Amer Soc Microbiology, Washington
T2  - Journal of Bacteriology
T1  - Critical residues for cofactor binding and catalytic activity in the aminoglycoside resistance methyltransferase Sgm
EP  - 5861
IS  - 17
SP  - 5855
VL  - 190
DO  - 10.1128/JB.00076-08
ER  - 

@article{
author = "Savić, Miloje and Ilić-Tomić, Tatjana and Macmaster, Rachel and Vasiljević, Branka and Conn, Graeme L.",
year = "2008",
abstract = "The 16S rRNA methyltransferase Sgm from "Micromonospora zionensis" confers resistance to aminoglycoside antibiotics by specific modification of the 30S ribosomal A site. Sgm is a member of the FmrO family, distant relatives of the S-adenosyl-L-methionine (SAM)-dependent RNA subfamily of methyltransferase enzymes. Using amino acid conservation across the FmrO family, seven putative key amino acids were selected for mutation to assess their role in forming the SAM cofactor binding pocket or in methyl group transfer. Each mutated residue was found to be essential for Sgm function, as no modified protein could effectively support bacterial growth in liquid media containing gentamicin or methylate 30S subunits in vitro. Using isothermal titration calorimetry, Sgm was found to bind SAM with a K-D (binding constant) of 17.6 mu M, and comparable values were obtained for one functional mutant (N179A) and four proteins modified at amino acids predicted to be involved in catalysis in methyl group transfer. In contrast, none of the G135, D156, or D182 Sgm mutants bound the cofactor, confirming their role in creating the SAM binding pocket. These results represent the first functional characterization of any FmrO methyltransferase and may provide a basis for a further structurefunction analysis of these aminoglycoside resistance determinants.",
publisher = "Amer Soc Microbiology, Washington",
journal = "Journal of Bacteriology",
title = "Critical residues for cofactor binding and catalytic activity in the aminoglycoside resistance methyltransferase Sgm",
pages = "5861-5855",
number = "17",
volume = "190",
doi = "10.1128/JB.00076-08"
}

Savić, M., Ilić-Tomić, T., Macmaster, R., Vasiljević, B.,& Conn, G. L.. (2008). Critical residues for cofactor binding and catalytic activity in the aminoglycoside resistance methyltransferase Sgm. in Journal of Bacteriology
Amer Soc Microbiology, Washington., 190(17), 5855-5861.
https://doi.org/10.1128/JB.00076-08

Savić M, Ilić-Tomić T, Macmaster R, Vasiljević B, Conn GL. Critical residues for cofactor binding and catalytic activity in the aminoglycoside resistance methyltransferase Sgm. in Journal of Bacteriology. 2008;190(17):5855-5861.
doi:10.1128/JB.00076-08 .

Savić, Miloje, Ilić-Tomić, Tatjana, Macmaster, Rachel, Vasiljević, Branka, Conn, Graeme L., "Critical residues for cofactor binding and catalytic activity in the aminoglycoside resistance methyltransferase Sgm" in Journal of Bacteriology, 190, no. 17 (2008):5855-5861,
https://doi.org/10.1128/JB.00076-08 . .