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-Structure paper
タイトル | 30S subunit recognition and G1405 modification by the aminoglycoside-resistance 16S ribosomal RNA methyltransferase RmtC. |
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ジャーナル・号・ページ | bioRxiv, Year 2023 |
掲載日 | 2023年4月30日 |
著者 | Pooja Srinivas / Meisam Nosrati / Natalia Zelinskaya / Debayan Dey / Lindsay R Comstock / Christine M Dunham / Graeme L Conn / |
PubMed 要旨 | Acquired ribosomal RNA (rRNA) methylation has emerged as a significant mechanism of aminoglycoside resistance in pathogenic bacterial infections. Modification of a single nucleotide in the ribosome ...Acquired ribosomal RNA (rRNA) methylation has emerged as a significant mechanism of aminoglycoside resistance in pathogenic bacterial infections. Modification of a single nucleotide in the ribosome decoding center by the aminoglycoside-resistance 16S rRNA (m G1405) methyltransferases effectively blocks the action of all 4,6-deoxystreptamine ring-containing aminoglycosides, including the latest generation of drugs. To define the molecular basis of 30S subunit recognition and G1405 modification by these enzymes, we used a S-adenosyl-L-methionine (SAM) analog to trap the complex in a post-catalytic state to enable determination of an overall 3.0 Ã… cryo-electron microscopy structure of the m G1405 methyltransferase RmtC bound to the mature Escherichia coli 30S ribosomal subunit. This structure, together with functional analyses of RmtC variants, identifies the RmtC N-terminal domain as critical for recognition and docking of the enzyme on a conserved 16S rRNA tertiary surface adjacent to G1405 in 16S rRNA helix 44 (h44). To access the G1405 N7 position for modification, a collection of residues across one surface of RmtC, including a loop that undergoes a disorder to order transition upon 30S subunit binding, induces significant distortion of h44. This distortion flips G1405 into the enzyme active site where it is positioned for modification by two almost universally conserved RmtC residues. These studies expand our understanding of ribosome recognition by rRNA modification enzymes and present a more complete structural basis for future development of strategies to inhibit m G1405 modification to re-sensitize bacterial pathogens to aminoglycosides. |
リンク | bioRxiv / PubMed:36993224 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.0 Å |
構造データ | EMDB-40051, PDB-8ghu: |
化合物 | ChemComp-MG: |
由来 |
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キーワード | RIBOSOME / 30S / RmtC / 16S rRNA methyltransferase |