RRC ID 5823
Author Tomikawa C, Yokogawa T, Kanai T, Hori H.
Title N7-Methylguanine at position 46 (m7G46) in tRNA from Thermus thermophilus is required for cell viability at high temperatures through a tRNA modification network.
Journal Nucleic Acids Res.
Abstract N(7)-methylguanine at position 46 (m(7)G46) in tRNA is produced by tRNA (m(7)G46) methyltransferase (TrmB). To clarify the role of this modification, we made a trmB gene disruptant (DeltatrmB) of Thermus thermophilus, an extreme thermophilic eubacterium. The absence of TrmB activity in cell extract from the DeltatrmB strain and the lack of the m(7)G46 modification in tRNA(Phe) were confirmed by enzyme assay, nucleoside analysis and RNA sequencing. When the DeltatrmB strain was cultured at high temperatures, several modified nucleotides in tRNA were hypo-modified in addition to the lack of the m(7)G46 modification. Assays with tRNA modification enzymes revealed hypo-modifications of Gm18 and m(1)G37, suggesting that the m(7)G46 positively affects their formations. Although the lack of the m(7)G46 modification and the hypo-modifications do not affect the Phe charging activity of tRNA(Phe), they cause a decrease in melting temperature of class I tRNA and degradation of tRNA(Phe) and tRNA(Ile). (35)S-Met incorporation into proteins revealed that protein synthesis in DeltatrmB cells is depressed above 70 degrees C. At 80 degrees C, the DeltatrmB strain exhibits a severe growth defect. Thus, the m(7)G46 modification is required for cell viability at high temperatures via a tRNA modification network, in which the m(7)G46 modification supports introduction of other modifications.
Volume 38(3)
Pages 942-57
Published 2010-1
DOI 10.1093/nar/gkp1059
PII gkp1059
PMID 19934251
PMC PMC2817472
MeSH Aminoacylation Bacterial Proteins / biosynthesis Bacterial Proteins / chemistry Gene Deletion Guanine / analogs & derivatives* Guanine / metabolism Hot Temperature* Methionine / metabolism Nucleic Acid Denaturation RNA Processing, Post-Transcriptional RNA, Transfer / chemistry* RNA, Transfer / metabolism RNA, Transfer, Phe / chemistry RNA, Transfer, Phe / metabolism Thermus thermophilus / enzymology* Thermus thermophilus / genetics Thermus thermophilus / growth & development tRNA Methyltransferases / genetics tRNA Methyltransferases / metabolism*
IF 11.147
Times Cited 28
DNA material Thermus thermophilus HB8 gene disruption plasmid TDs08C11 (THR023259)