Biomaterial Database

Nucleotides that determine Escherichia coli tRNA(Arg) and tRNA(Lys) acceptor identities revealed by analyses of mutant opal and amber suppressor tRNAs. 1990

W H McClain, and K Foss, and R A Jenkins, and J Schneider

Department of Bacteriology, University of Wisconsin, Madison 53706-1567.

We have constructed an opal suppressor system in Escherichia coli to complement an existing amber suppressor system to study the structural basis of tRNA acceptor identity, particularly the role of middle anticodon nucleotide at position 35. The opal suppressor tRNA contains a UCA anticodon and the mRNA of the suppressed protein (which is easily purified and sequenced) contains a UGA nonsense triplet. Opal suppressor tRNAs of two tRNA(Arg) isoacceptor sequences each gave arginine in the suppressed protein, while the corresponding amber suppressors with U35 in their CUA anticodons each gave arginine plus a second amino acid in the suppressed protein. Since C35 but not U35 is present in the anticodon of wild-type tRNA(Arg) molecules, while the first anticodon position contains either C34 or U34, these results establish that C35 contributes to tRNA(Arg) acceptor identity. Initial characterizations of opal suppressor tRNA(Arg) mutants by suppression efficiency measurements suggest that the fourth nucleotide from the 3' end of tRNA(Arg) (A73 or G73 in different isoacceptors) also contributes to tRNA(Arg) acceptor identity. Wild-type and mutant versions of opal and amber tRNA(Lys) suppressors were examined, revealing that U35 and A73 are important determinants of tRNA(Lys) acceptor identity. Several possibilities are discussed for the general significance of having tRNA acceptor identity in the same positions in different tRNA acceptor types, as exemplified by positions 35 and 73 in tRNA(Arg) and tRNA(Lys).

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D000926	Anticodon	The sequential set of three nucleotides in TRANSFER RNA that interacts with its complement in MESSENGER RNA, the CODON, during translation in the ribosome.	Anticodons
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012343	RNA, Transfer	The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.	Suppressor Transfer RNA,Transfer RNA,tRNA,RNA, Transfer, Suppressor,Transfer RNA, Suppressor,RNA, Suppressor Transfer
D012347	RNA, Transfer, Arg	A transfer RNA which is specific for carrying arginine to sites on the ribosomes in preparation for protein synthesis.	Arginine-Specific tRNA,Transfer RNA, Arg,tRNAArg,tRNA(Arg),Arg Transfer RNA,Arginine Specific tRNA,RNA, Arg Transfer,tRNA, Arginine-Specific
D012357	RNA, Transfer, Lys	A transfer RNA which is specific for carrying lysine to sites on the ribosomes in preparation for protein synthesis.	Lysine-Specific tRNA,Transfer RNA, Lys,tRNALys,tRNA(Lys),Lys Transfer RNA,Lysine Specific tRNA,RNA, Lys Transfer,tRNA, Lysine-Specific
D016153	Genes, Suppressor	Genes that have a suppressor allele or suppressor mutation (SUPPRESSION, GENETIC) which cancels the effect of a previous mutation, enabling the wild-type phenotype to be maintained or partially restored. For example, amber suppressors cancel the effect of an AMBER NONSENSE MUTATION.	Amber Suppressor Genes,Frameshift Suppressor Genes,Genes, Amber Suppressor,Genes, Frameshift Suppressor,Genes, Nonsense Mutation Suppressor,Genes, Ochre Suppressor,Genes, Second-Site Suppressor,Nonsense Mutation Suppressor Genes,Ochre Suppressor Genes,Second-Site Suppressor Genes,Genes, Opal Suppressor,Suppressor Genes,Amber Suppressor Gene,Frameshift Suppressor Gene,Gene, Amber Suppressor,Gene, Frameshift Suppressor,Gene, Ochre Suppressor,Gene, Opal Suppressor,Gene, Second-Site Suppressor,Gene, Suppressor,Genes, Second Site Suppressor,Ochre Suppressor Gene,Opal Suppressor Gene,Opal Suppressor Genes,Second Site Suppressor Genes,Second-Site Suppressor Gene,Suppressor Gene,Suppressor Gene, Amber,Suppressor Gene, Frameshift,Suppressor Gene, Ochre,Suppressor Gene, Opal,Suppressor Gene, Second-Site,Suppressor Genes, Amber,Suppressor Genes, Frameshift,Suppressor Genes, Ochre,Suppressor Genes, Opal,Suppressor Genes, Second-Site