Novel E. coli mutants deficient in biosynthesis of 5-methylaminomethyl-2-thiouridine.
AUTOR(ES)
Elseviers, D
RESUMO
Novel E. coli mutants deficient in biosynthesis of 5- methylaminomethyl -2-thiouridine were isolated based on a phenotype of reduced readthrough at UAG codons. They define 2 new loci trmE and trmF , near 83' on the E. coli map. These mutants are different from strains carrying trmC mutations, which are known to confer a methylation deficiency in biosynthesis of 5- methylaminomethyl -2-thiouridine. tRNA from mutants carrying trmE or trmF mutations was shown to carry 2-thiouridine instead of 5- methylaminomethyl -2-thiouridine. This deficiency affects the triplet binding properties of the mutant tRNA. Our results suggest that the 5- methylaminomethyl group stabilizes the basepairing of this modified nucleotide with G, most likely through direct interaction with the ribosomal binding site(s).
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=318766Documentos Relacionados
- Antisuppressor mutation in Escherichia coli defective in biosynthesis of 5-methylaminomethyl-2-thiouridine.
- Escherichia coli mutants with defects in the biosynthesis of 5-methylaminomethyl-2-thio-uridine or 1-methylguanosine in their tRNA.
- SOS mutator effect in E. coli mutants deficient in mismatch correction.
- Isolation of single-site Escherichia coli mutants deficient in thiamine and 4-thiouridine syntheses: identification of a nuvC mutant.
- BIOSYNTHESIS OF THE COAT PROTEIN OF COLIPHAGE f2 BY E. COLI EXTRACTS*