7BYY

Crystal structure of bacterial toxin

7BYY の概要

• エントリーDOI: 10.2210/pdb7byy/pdb
• 分子名称: Acetyltransferase (2 entities in total)
• 機能のキーワード: acetyltranferase, toxin, transferase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 83828.77

構造登録者

Zhang, C.,Yashiro, Y.,Tomita, K. (登録日: 2020-04-25, 公開日: 2020-06-03, 最終更新日: 2023-11-29)

主引用文献

Zhang, C.,Yashiro, Y.,Sakaguchi, Y.,Suzuki, T.,Tomita, K.
Substrate specificities of Escherichia coli ItaT that acetylates aminoacyl-tRNAs.
Nucleic Acids Res., 48:7532-7544, 2020

PubMed Abstract: Escherichia coli ItaT toxin reportedly acetylates the α-amino group of the aminoacyl-moiety of Ile-tRNAIle specifically, using acetyl-CoA as an acetyl donor, thereby inhibiting protein synthesis. The mechanism of the substrate specificity of ItaT had remained elusive. Here, we present functional and structural analyses of E. coli ItaT, which revealed the mechanism of ItaT recognition of specific aminoacyl-tRNAs for acetylation. In addition to Ile-tRNAIle, aminoacyl-tRNAs charged with hydrophobic residues, such as Val-tRNAVal and Met-tRNAMet, were acetylated by ItaT in vivo. Ile-tRNAIle, Val-tRNAVal and Met-tRNAMet were acetylated by ItaT in vitro, while aminoacyl-tRNAs charged with other hydrophobic residues, such as Ala-tRNAAla, Leu-tRNALeu and Phe-tRNAPhe, were less efficiently acetylated. A comparison of the structures of E. coli ItaT and the protein N-terminal acetyltransferase identified the hydrophobic residues in ItaT that possibly interact with the aminoacyl moiety of aminoacyl-tRNAs. Mutations of the hydrophobic residues of ItaT reduced the acetylation activity of ItaT toward Ile-tRNAIlein vitro, as well as the ItaT toxicity in vivo. Altogether, the size and shape of the hydrophobic pocket of ItaT are suitable for the accommodation of the specific aminoacyl-moieties of aminoacyl-tRNAs, and ItaT has broader specificity toward aminoacyl-tRNAs charged with certain hydrophobic amino acids.

PubMed: 32501503
DOI: 10.1093/nar/gkaa487

実験手法

X-RAY DIFFRACTION (2.799 Å)