Temperature-dependent biosynthesis of 2-thioribothymidine of Thermus thermophilus tRNA.
2-Thioribothymidine (s(2)T) is a modified nucleoside of U, specifically found at position 54 of tRNAs from extreme thermophilic microorganisms. The function of the 2-thiocarbonyl group of s(2)T54 is thermostabilization of the three-dimensional structure of tRNA; however, its biosynthesis has not been clarified until now. Using an in vivo tRNA labeling experiment, we demonstrate that the sulfur atom of s(2)T in tRNA is derived from cysteine or sulfate. We attempted to reconstitute 2-thiolation of s(2)T in vitro, using a cell extract of Thermus thermophilus. Specific 2-thiolation of ribothymidine, at position 54, was observed in vitro, in the presence of ATP. Using this assay, we found a strong temperature dependence of the 2-thiolation reaction in vitro as well as expression of 2-thiolation enzymes in vivo. These results suggest that the variable content of s(2)T in vivo at different temperatures may be explained by the above characteristics of the enzymes responsible for the 2-thiolation reaction. Furthermore, we found that another posttranscriptionally modified nucleoside, 1-methyladenosine at position 58, is required for the efficient 2-thiolation of ribothymidine 54 both in vivo and in vitro.
Shigi
Naoki
N
Biological Information Research Center, National Institute of Advanced Industrial Science and Technology, 2-42 Aomi, Koto-ku, Tokyo 135-0064, Japan.
Suzuki
Tsutomu
T
Terada
Takaho
T
Shirouzu
Mikako
M
Yokoyama
Shigeyuki
S
Watanabe
Kimitsuna
K
D000241:Adenosine / Q000031:analogs & derivatives / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000737:chemistry; D001426:Bacterial Proteins / Q000235:genetics; D001665:Binding Sites; D013437:Carbon-Sulfur Lyases / Q000235:genetics; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D003545:Cysteine / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D008190:Lyases / Q000235:genetics; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009841:Oligonucleotides / Q000737:chemistry; D011485:Protein Binding; D012313:RNA / Q000737:chemistry; D012323:RNA Processing, Post-Transcriptional; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011995:Recombination, Genetic; D017423:Sequence Analysis, RNA; D013431:Sulfates / Q000737:chemistry; D013466:Sulfurtransferases / Q000235:genetics; D013696:Temperature; D016963:Thermus thermophilus / Q000378:metabolism*; D013891:Thiouridine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D014529:Uridine / Q000031:analogs & derivatives / Q000737:chemistry; D012359:tRNA Methyltransferases / Q000235:genetics
D001426:Bacterial Proteins; D003470:Culture Media; D009841:Oligonucleotides; D013431:Sulfates; D013891:Thiouridine; C009182:ribothymidine; C002230:1-methyladenosine; C022856:2-thioribothymidine; D012313:RNA; D000255:Adenosine Triphosphate; D012343:RNA, Transfer; C089041:N(2),N(2)-dimethylguanosine-26-methyltransferase; D012359:tRNA Methyltransferases; D013466:Sulfurtransferases; C107110:ThiI protein, bacteria; D008190:Lyases; D013437:Carbon-Sulfur Lyases; C080546:cysteine desulfurase; C034278:selenocysteine lyase; D000241:Adenosine; D003545:Cysteine; D014529:Uridine