Naslov
Modelling and mutagenesis of aminoglycoside resistance methyltransferase Sgm

Autori
Maravić Vlahoviček, Gordana ; Čubrilo, Sonja ; Tkaczuk, Karolina L. ; Bujnicki, Janusz M.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
John Innes/Rudjer Bošković Summer School on “ Microbial Genomics and Secondary Metabolites”

Mjesto i datum
Split, Hrvatska, 23.06.2007. - 01.07.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
antibiotic resistance; 16S rRNA methylation; methyltransferase Sgm

Sažetak
Methyltransferases that carry out posttranscriptional N7-methylation of G1405 in 16S rRNA confer bacterial resistance to aminoglycoside antibiotics, including kanamycin and gentamicin. Genes encoding enzyme from the Arm (aminoglycoside resistance methyltransferases) family have been recently found to spread by horizontal gene transfer between various human pathogens. The knowledge of the Arm protein structure would lay the groundwork for the development of potential resistance inhibitors, which could be used to restore the potential of aminoglycosides to act against the resistant pathogens. We analyzed the sequence-function relationships of Sgm MTase, a member of the Arm family, by limited proteolysis and site-directed and random mutagenesis. We have also modeled the structure of Sgm using bioinformatics techniques and used the model to provide a structural context for experimental results. We found that Sgm comprises two domains and we characterized a number of functionally compromised point mutants with substitutions of invariant or conserved residues. Our study provides a low-resolution (residue-level) model of sequence-structure-function relationships in the Arm family of enzymes and reveals the cofactor-binding and substrate-binding sites. These functional regions will be prime targets for further experimental and theoretical studies aiming at defining the reaction mechanism of m7G1405 methylation, increasing the resolution of the model and developing Arm-specific inhibitors.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA