TY - JOUR
T1 - Role of the extra G-C pair at the end of the acceptor stem of tRNAHb in aminoacylation
AU - Himeno, Hyouta
AU - Hasegawa, Tsunemi
AU - Ueda, Takuya
AU - Watanabe, Kimitsuna
AU - Miura, Kin Ichiro
AU - Shimizu, Mikio
N1 - Funding Information:
ACKMOtLEDGBEHTS We thank Dr. F. W. Studler of Brookhaven National Laboratory for generously providing E. coll strain BL21 and kind Instruction on the preparation of T7 RJiA polyaerase. This work was supported by a Grant-in-Aid for Scientific Research on Priority Areas fron the Ministry of Education, Science and Culture, Japan.
PY - 1989/10/11
Y1 - 1989/10/11
N2 - All sequenced histidine tRNAs have one additional nucleotide at the 5′ end compared with other tRNA species. To Investigate the role of this unique structure in aainoacylation, we constructed in vitro transcripts corresponding to the E. coli histidine tRNA sequence and its variants at the G-1-C73 base pair, by using T7 RNA polymerase transcription systm. A transcript having a wild-type sequence with no modified bases was a good substrate for histidyl-tRNA synthetase (HisRS), and aminoacylation activity was affected by introduction of a triphosphate at the 5′ terminus. Base replacements at position 73 caused a marked decrease of Vmax, and deletion and substitution of the G-1 had a remarkable effect on the aminoacylation. A mutant having an A-1-U73 pair was also not a good substrate for HisRS. Comparison among G-1-deficient mutants showed that A was preferable rather than C as the base at position 73. These data demonstrate that the set of the G-1-C73 pair at the end of the acceptor stem of histidine tRNA is crucial for the catalytic process of aminoacylation.
AB - All sequenced histidine tRNAs have one additional nucleotide at the 5′ end compared with other tRNA species. To Investigate the role of this unique structure in aainoacylation, we constructed in vitro transcripts corresponding to the E. coli histidine tRNA sequence and its variants at the G-1-C73 base pair, by using T7 RNA polymerase transcription systm. A transcript having a wild-type sequence with no modified bases was a good substrate for histidyl-tRNA synthetase (HisRS), and aminoacylation activity was affected by introduction of a triphosphate at the 5′ terminus. Base replacements at position 73 caused a marked decrease of Vmax, and deletion and substitution of the G-1 had a remarkable effect on the aminoacylation. A mutant having an A-1-U73 pair was also not a good substrate for HisRS. Comparison among G-1-deficient mutants showed that A was preferable rather than C as the base at position 73. These data demonstrate that the set of the G-1-C73 pair at the end of the acceptor stem of histidine tRNA is crucial for the catalytic process of aminoacylation.
UR - http://www.scopus.com/inward/record.url?scp=0024472840&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0024472840&partnerID=8YFLogxK
U2 - 10.1093/nar/17.19.7855
DO - 10.1093/nar/17.19.7855
M3 - Article
C2 - 2678006
AN - SCOPUS:0024472840
SN - 0305-1048
VL - 17
SP - 7855
EP - 7863
JO - Nucleic Acids Research
JF - Nucleic Acids Research
IS - 19
ER -