%0 Journal Article
%T Biological function of modified nucleotides T54 and Ψ55 of yeast tRNAAla
%A JIANG Huaqi
%A JIN Youxin
%A WANG Debao
%A
%J 中国科学C辑(英文版)
%D 1997
%I Springer
%X The 3′ half molecule of yeast tRNAAla (nucleotides 36–75) was hybridized with a DNA fragment (5′GGAATCGAACC 3′) and the hybrid was then digested withE. coli RNase H (from Boehringer). The enzyme can specifically cleave the 3′ half molecule at the 3′ side of nucleotide Ψ55, thus a fragment C36-Ψ55 was prepared. The 3′-terminal T or TΨ of this fragment was removed by one or two cycles of periodate oxidation and β-elimination. The products were fragments C36-T54 and C36-G53. Three yeast tRNAAla fragments C56-A76, U55-A76 (with Ψ55 replaced by U), U54-A76 (with T54Ψ55 replaced by UU) were synthesized and ligated with three prepared fragments (C36-Ψ55, C36-T54 and C36-G53) respectively by T4 RNA ligase. The products were further ligated with the 5′ half molecule (nu-cleotides 1–35). Using this method, one reconstituted yeast tRNAAla (tRNAr) and two yeast tRNAALa analogs: (i) tRNAa with U55 instead of Ψ55; (ii) tRNAb with U54U55 instead of T54Ψ55 were synthesized. The charging and incorporation activities of these three tRNAs were determined. In comparison with the reconstituted tRNA, the charging activity was 75% for tRNAa and 45% for tRNAb and the incorporation activity was 65% for tRNAa and 70% for tRNAb. These results suggest that the modified nucleotides T54 and Ψ55 play an important role in yeast tRNAAla function. Project supported by the National Natural Science Foundation of China.
%K yeast tRNAAla
%K biological function
%K modified nucleotides
%K T54 and Ψ
%K 55
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=180CF3A72E750F3261A8A60EDC957784&aid=E554ADF6D7ACAD9785C003670EA7194F&yid=5370399DC954B911&vid=1371F55DA51B6E64&iid=B31275AF3241DB2D&sid=6D6B4A516C7DB6EE&eid=E406B4E9A1BA9D8C&journal_id=1674-7305&journal_name=ScienceChina.Lifesciences&referenced_num=0&reference_num=15