Naslov
Mutations in the A site of 16S rRNA affect the interaction between aminoglycoside resistance methyltransferase Sgm and bacterial ribosome

Autori
Čubrilo, Sonja ; Maravić Vlahoviček, Gordana

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

Izvornik
Book of abstracts / Frece, Jadranka ; Kos, Blaženka ; Mrša, Vladimir - Zagreb : Hrvatsko mikrobiološko društvo, 2010

ISBN
978-953-7778-00-2

Skup
Central European Symposium on Industrial Microbiology and Microbial Ecology “Power of Microbes in Industry and Environment”

Mjesto i datum
Malinska, Hrvatska, 22.09.2010. - 25.09.2010

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
16S rRNA; A site; ribosome; mutations; aminoglycoside resistance; methyltransferase Sgm

Sažetak
Sgm methyltransferase from the natural producer of aminoglycoside antibiotic sisomicin, actinomycete Micromonospora zionensis, modifies nucleotide G1405 in the A site of 16S rRNA, conferring high-level resistance to aminoglycosides because of the inability of the drugs to bind to their target site in the 30 S ribosomal subunit. Sgm methyltransferase is a member of Arm family of enzymes. Besides the enzymes from the natural producers of aminoglycoside antibiotics, members of the Arm family include enzymes that were recently found to be spreading by horizontal transfer in growing number of clinical strains, which significantly reduces the odds of a successful treatment of severe bacterial infections. A site of 16S ribosomal RNA contains highly conserved nucleotide sequences due to involvement of this ribosomal region in the decoding process. Previously, there have been attempts on elucidating the impact of universally conserved single nucleotides or shorter sequences in the A site of 16S rRNA on the essential ribosomal functions in experimental systems using mixed population of normal and mutated ribosomes in bacterial cells. In this work, we introduced various 16S rRNA mutations in E. coli strain carrying only one copy of 16S rRNA gene, thus creating cells with a uniform population of mutated ribosomes. We determined generation time and investigated the ability of these cells to grow in the presence of various concentrations of aminoglycoside kanamycin. We then introduced actively expressing methyltransferase Sgm into these cells and monitored the impact of the mutations on the methyltransferase activity. Our results indicate that the mutations introduced in the A site of 16S rRNA affect the interaction between aminoglycoside resistance methyltransferase Sgm and bacterial ribosome. These findings are leading towards the defining of the recognition motif of methyltransferase Sgm on the bacterial ribosome, which will help to construct effective inhibitors of the members of Arm family of enzymes, thus fighting aminoglycoside resistance.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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