Suppressors of lysine codons may be misacylated lysine tRNAs.

نویسندگان

  • E J Murgola
  • F T Pagel
چکیده

We describe a novel class of missense suppressors that read the codons for lysine at two positions (211 and 234) in the trpA polypeptide of Escherichia coli. The suppressor mutations are highly linked to lysT, a gene for lysine tRNA. The results suggest that the suppressors are misacylated lysine tRNAs that carry glycine or alanine. The mutant codons are apparently suppressed better at position 211 than at position 234, indicating the existence of codon context effects in missense suppression.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The presence of pseudouridine in the anticodon alters the genetic code: a possible mechanism for assignment of the AAA lysine codon as asparagine in echinoderm mitochondria.

It has been inferred from DNA sequence analyses that in echinoderm mitochondria not only the usual asparagine codons AAU and AAC, but also the usual lysine codon AAA, are translated as asparagine by a single mitochondrial (mt) tRNAAsn with the anticodon GUU. Nucleotide sequencing of starfish mt tRNAAsn revealed that the anticodon is GPsiU, U35 at the anticodon second position being modified to ...

متن کامل

Ribosomes slide on lysine-encoding homopolymeric A stretches

Protein output from synonymous codons is thought to be equivalent if appropriate tRNAs are sufficiently abundant. Here we show that mRNAs encoding iterated lysine codons, AAA or AAG, differentially impact protein synthesis: insertion of iterated AAA codons into an ORF diminishes protein expression more than insertion of synonymous AAG codons. Kinetic studies in E. coli reveal that differential ...

متن کامل

Strictly Conserved Lysine of Prolyl-tRNA Synthetase Editing Domain Facilitates Binding and Positioning of Misacylated tRNAPro

To ensure high fidelity in translation, many aminoacyl-tRNA synthetases, enzymes responsible for attaching specific amino acids to cognate tRNAs, require proof-reading mechanisms. Most bacterial prolyl-tRNA synthetases (ProRSs) misactivate alanine and employ a post-transfer editing mechanism to hydrolyze Ala-tRNA(Pro). This reaction occurs in a second catalytic site (INS) that is distinct from ...

متن کامل

SURVEY AND SUMMARY Decoding the genome: a modi®ed view

Transfer RNA's role in decoding the genome is critical to the accuracy and ef®ciency of protein synthesis. Though modi®ed nucleosides were identi®ed in RNA 50 years ago, only recently has their importance to tRNA's ability to decode cognate and wobble codons become apparent. RNA modi®cations are ubiquitous. To date, some 100 different posttranslational modi®cations have been identi®ed. Modi®cat...

متن کامل

The role of modifications in codon discrimination by tRNAUUU

The natural modification of specific nucleosides in many tRNAs is essential during decoding of mRNA by the ribosome. For example, tRNAUUU requires the modification N6-threonylcarbamoyladenosine at position 37 (t6A37), adjacent and 3′ to the anticodon, to bind AAA in the A site of the ribosomal 30S subunit. Moreover, it can only bind both AAA and AAG lysine codons when doubly modified with t6A37...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of bacteriology

دوره 156 2  شماره 

صفحات  -

تاریخ انتشار 1983