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ID 119492
Title Alternative
Substrate RNA specificity of ArcS
Author
Fujita, Shu Ehime University
Sugio, Yuzuru Ehime University
Kawamura, Takuya Ehime University
Yamagami, Ryota Ehime University
Oka, Natsuhisa Gifu University
Yokogawa, Takashi Gifu University
Hori, Hiroyuki Ehime University
Content Type
Journal Article
Description
Archaeosine (G+) is an archaea-specific tRNA modification synthesized via multiple steps. In the first step, archaeosine tRNA guanine transglucosylase (ArcTGT) exchanges the G15 base in tRNA with 7-cyano-7-deazaguanine (preQ0). In Euryarchaea, preQ015 in tRNA is further modified by archaeosine synthase (ArcS). Thermococcus kodakarensis ArcS catalyzes a lysine-transfer reaction to produce preQ0-lysine (preQ0-Lys) as an intermediate. The resulting preQ0-Lys15 in tRNA is converted to G+15 by a radical S-adenosyl-L-methionine enzyme for archaeosine formation (RaSEA), which forms a complex with ArcS. Here, we focus on the substrate tRNA recognition mechanism of ArcS. Kinetic parameters of ArcS for lysine and tRNA-preQ0 were determined using a purified enzyme. RNA fragments containing preQ0 were prepared from Saccharomyces cerevisiae tRNAPhe-preQ015. ArcS transferred 14C-labeled lysine to RNA fragments. Furthermore, ArcS transferred lysine to preQ0 nucleoside and preQ0 nucleoside 5′-monophosphate. Thus, the L-shaped structure and the sequence of tRNA are not essential for the lysine-transfer reaction by ArcS. However, the presence of D-arm structure accelerates the lysine-transfer reaction. Because ArcTGT from thermophilic archaea recognizes the common D-arm structure, we expected the combination of T. kodakarensis ArcTGT and ArcS and RaSEA complex would result in the formation of preQ0-Lys15 in all tRNAs. This hypothesis was confirmed using 46 T. kodakarensis tRNA transcripts and three Haloferax volcanii tRNA transcripts. In addition, ArcTGT did not exchange the preQ0-Lys15 in tRNA with guanine or preQ0 base, showing that formation of tRNA-preQ0-Lys by ArcS plays a role in preventing the reverse reaction in G+ biosynthesis.
Journal Title
Journal of Biological Chemistry
ISSN
00219258
1083351X
NCID
AA1202441X
Publisher
American Society for Biochemistry and Molecular Biology|Elsevier
Volume
300
Issue
8
Start Page
107505
Published Date
2024-06-27
Rights
This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Publisher
departments
Science and Technology