SITE-DIRECTED INVITRO REPLACEMENT OF NUCLEOSIDES IN THE ANTICODON LOOP OF TRANSFER-RNA - APPLICATION TO THE STUDY OF STRUCTURAL REQUIREMENTS FOR QUEUINE INSERTASE ACTIVITY
SITE-DIRECTED INVITRO REPLACEMENT OF NUCLEOSIDES IN THE ANTICODON LOOP OF TRANSFER-RNA - APPLICATION TO THE STUDY OF STRUCTURAL REQUIREMENTS FOR QUEUINE INSERTASE ACTIVITY
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DOI：
10.1002/j.1460-2075.1983.tb01551.x
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发表时间：
1983-01-01
期刊：
影响因子：
11.4
通讯作者：
GROSJEAN, H
中科院分区：
文献类型：
--
作者：
CARBON, P;HAUMONT, E;GROSJEAN, H
The specificity of the enzymes Q-insertase and mannosyl-Q transferase that replace the guanosine at position 34 (wobble base) in the anticodon of several tRNA by Q or mannosyl-Q derivatives was investigated. The normal anticodon of yeast .**GRAPHIC**. yeast .**GRAPHIC**. and yeast .**GRAPHIC**. With yeast .**GRAPHIC**. 1 or several nucleotides in the vicinity of G34 was replaced by 1 of the 4 canonical nucleotides or by pseudouridylic acid; a tRNAAsp with 8 bases instead of 7 in the anticodon loop was also constructed. With yeast .**GRAPHIC**. and yeast .**GRAPHIC**. their anticodon was replaced by the trinucleotide GUC, coding for aspartic acid. The chimerical tRNA were microinjected into the cytoplasm of Xenopus laevis oocytes and after 72 h the amount of Q34 and mannosyl-Q34 incorporated was measured. The U33G34U35 sequence, within an anticodon loop of 7 bases in chimerical yeast .**GRAPHIC**. .**GRAPHIC**. or .**GRAPHIC**. is the main determinant for Q-insertase activity as position 34; the rest of the tRNA sequence has only a slight influence. For mannosyl-Q transferase, however, a much broader structural feature of the tRNA than just the U33G34U35 sequence is important for the efficiency of Q34 transformation into mannosyl-Q34.
