Relationship between the structure and function of Escherichia coli initiator tRNA.
Through functional studies of mutant tRNAs, we have identified sequence and/or structural features important for specifying the many distinctive properties of E coli initiator tRNA. Many of the mutant tRNAs contain an anticodon sequence change from CAU-->CUA and are now substrates for E coli glutaminyl-tRNA synthetase (GlnRS). We describe here the effect of further mutating the discriminator base 73 and nucleotide 72 at the end of the acceptor stem on: i) recognition of the mutant tRNAs by E coli GlnRS; ii) recognition by E coli methionyl-tRNA transformylase; and iii) activity of the mutant tRNAs in initiation in E coli. For GlnRS recognition, our results are, in general, consistent with interactions found in the crystal structure of the E coli GlnRS-glutamine tRNA complex. The results also support our previous conclusion that formylation of initiator tRNA is important for its function in initiation.
Dyson
M R
MR
Institute of Cell and Molecular Biology, University of Edinburgh, UK.
Mandal
N
N
RajBhandary
U L
UL
D000217:Acyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D019877:Hydroxymethyl and Formyl Transferases; D015151:Immunoblotting; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D010442:Peptide Chain Initiation, Translational; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012358:RNA, Transfer, Met; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D012329:RNA, Bacterial; D012346:RNA, Transfer, Amino Acyl; D012358:RNA, Transfer, Met; C024988:tRNA, formylmethionine-; D019877:Hydroxymethyl and Formyl Transferases; C021561:methionyl-tRNA formyltransferase; D000217:Acyltransferases; D000604:Amino Acyl-tRNA Synthetases; C020659:glutaminyl-tRNA synthetase