5BW4

Crystal structure of the 16S rRNA (adenine(1408)-N(1))-methyltransferase W203A mutant with cosubstrate SAM from Catenulisporales acidiphilia

5BW4 の概要

• エントリーDOI: 10.2210/pdb5bw4/pdb
• 関連するPDBエントリー: 5BW5
• 分子名称: 16S rRNA (adenine(1408)-N(1))-methyltransferase, S-ADENOSYLMETHIONINE (3 entities in total)
• 機能のキーワード: methyltransferase, ribosome, aminoglycoside resistance, transferase
• 由来する生物種: Catenulispora acidiphila
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 57819.83

構造登録者

Witek, M.A.,Conn, G.L. (登録日: 2015-06-05, 公開日: 2016-04-20, 最終更新日: 2023-09-27)

主引用文献

Witek, M.A.,Conn, G.L.
Functional dichotomy in the 16S rRNA (m1A1408) methyltransferase family and control of catalytic activity via a novel tryptophan mediated loop reorganization.
Nucleic Acids Res., 44:342-353, 2016

PubMed Abstract: Methylation of the bacterial small ribosomal subunit (16S) rRNA on the N1 position of A1408 confers exceptionally high-level resistance to a broad spectrum of aminoglycoside antibiotics. Here, we present a detailed structural and functional analysis of the Catenulisporales acidiphilia 16S rRNA (m(1)A1408) methyltransferase ('CacKam'). The apo CacKam structure closely resembles other m(1)A1408 methyltransferases within its conserved SAM-binding fold but the region linking core β strands 6 and 7 (the 'β6/7 linker') has a unique, extended structure that partially occludes the putative 16S rRNA binding surface, and sequesters the conserved and functionally critical W203 outside of the CacKam active site. Substitution of conserved residues in the SAM binding pocket reveals a functional dichotomy in the 16S rRNA (m(1)A1408) methyltransferase family, with two apparently distinct molecular mechanisms coupling cosubstrate/ substrate binding to catalytic activity. Our results additionally suggest that CacKam exploits the W203-mediated remodeling of the β6/7 linker as a novel mechanism to control 30S substrate recognition and enzymatic turnover.

PubMed: 26609134
DOI: 10.1093/nar/gkv1306

実験手法

X-RAY DIFFRACTION (2.1 Å)