Jaanus Remme - Profile on Academia.edu (original) (raw)
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Charité - Universitätsmedizin Berlin / Charité Medical University Berlin
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Papers by Jaanus Remme
Journal of Molecular Biology, 1997
Escherichia coli ribosomes with an A to U transversion at nucleotide 1067 of their 23 S rRNA are ... more Escherichia coli ribosomes with an A to U transversion at nucleotide 1067 of their 23 S rRNA are impaired in their effective association rate constants (k cat /K M ) for both EF-Tu and EF-G binding. In addition, the times that EF-G and EF-Tu spend on the ribosome during elongation are sig-ni®cantly increased by the A to U transversion. The U1067 mutation impairs EF-Tu function more than EF-G function. The increase in the time that EF-Tu remains bound to ribosome is caused, both by a slower rate of GTP-hydrolysis in ternary complex and by a slower EF-Tu Á GDP release from the mutated ribosomes. There is, at the same time, no change in ribosomal accuracy for aminoacyl-tRNA recognition. With support from these new data we propose that nucleotide 1067 is part of the ribosomal A-site where it directly interacts with both EF-G and EF-Tu.
FEBS Letters, 1984
Escherichia coli SO S ribosomal subunits were reconstituted with and without protein L16 present.... more Escherichia coli SO S ribosomal subunits were reconstituted with and without protein L16 present. The latter particles, although active in puromycin reaction, were unable to use CACCA-Phe as an acceptor substrate. We also found that L16 interacts directly with this ohgonucleotide and, in the complex with tRNA, protects its 3'-end from pancreatic ribonuclease digestion. We suggest that the role of L16 is in the fixation of the aminoacyl stem of tRNA to the ribosome at its A-site.
Cell reports, Jan 23, 2014
Bacterial ribosomes stall on polyproline stretches and require the elongation factor P (EF-P) to ... more Bacterial ribosomes stall on polyproline stretches and require the elongation factor P (EF-P) to relieve the arrest. Yet it remains unclear why evolution has favored the development of EF-P rather than selecting against the occurrence of polyproline stretches in proteins. We have discovered that only a single polyproline stretch is invariant across all domains of life, namely a proline triplet in ValS, the tRNA synthetase, that charges tRNA(Val) with valine. Here, we show that expression of ValS in vivo and in vitro requires EF-P and demonstrate that the proline triplet located in the active site of ValS is important for efficient charging of tRNA(Val) with valine and preventing formation of mischarged Thr-tRNA(Val) as well as efficient growth of E. coli in vivo. We suggest that the critical role of the proline triplet for ValS activity may explain why bacterial cells coevolved the EF-P rescue system.
Febs Letters, 1983
Two large proteolytic fragments of Escherichia coli 50 S ribosomal subunit protein L16 were gener... more Two large proteolytic fragments of Escherichia coli 50 S ribosomal subunit protein L16 were generated by limited hydrolysis with chymotrypsin (missing 9 N-terminal amino acids) and trypsin (missing 16 Nterminal amino acids). It was found that while intact L16 and its chymotryptic fragment both interact with tRNA (Kd = 5.4 x lo-' M), the tryptic fragment does not. These results are interpreted in terms of possible significance of the residues lo-16 in the peptidyl transferase activity.
Journal of Molecular Biology, 1997
Escherichia coli ribosomes with an A to U transversion at nucleotide 1067 of their 23 S rRNA are ... more Escherichia coli ribosomes with an A to U transversion at nucleotide 1067 of their 23 S rRNA are impaired in their effective association rate constants (k cat /K M ) for both EF-Tu and EF-G binding. In addition, the times that EF-G and EF-Tu spend on the ribosome during elongation are sig-ni®cantly increased by the A to U transversion. The U1067 mutation impairs EF-Tu function more than EF-G function. The increase in the time that EF-Tu remains bound to ribosome is caused, both by a slower rate of GTP-hydrolysis in ternary complex and by a slower EF-Tu Á GDP release from the mutated ribosomes. There is, at the same time, no change in ribosomal accuracy for aminoacyl-tRNA recognition. With support from these new data we propose that nucleotide 1067 is part of the ribosomal A-site where it directly interacts with both EF-G and EF-Tu.
FEBS Letters, 1984
Escherichia coli SO S ribosomal subunits were reconstituted with and without protein L16 present.... more Escherichia coli SO S ribosomal subunits were reconstituted with and without protein L16 present. The latter particles, although active in puromycin reaction, were unable to use CACCA-Phe as an acceptor substrate. We also found that L16 interacts directly with this ohgonucleotide and, in the complex with tRNA, protects its 3'-end from pancreatic ribonuclease digestion. We suggest that the role of L16 is in the fixation of the aminoacyl stem of tRNA to the ribosome at its A-site.
Cell reports, Jan 23, 2014
Bacterial ribosomes stall on polyproline stretches and require the elongation factor P (EF-P) to ... more Bacterial ribosomes stall on polyproline stretches and require the elongation factor P (EF-P) to relieve the arrest. Yet it remains unclear why evolution has favored the development of EF-P rather than selecting against the occurrence of polyproline stretches in proteins. We have discovered that only a single polyproline stretch is invariant across all domains of life, namely a proline triplet in ValS, the tRNA synthetase, that charges tRNA(Val) with valine. Here, we show that expression of ValS in vivo and in vitro requires EF-P and demonstrate that the proline triplet located in the active site of ValS is important for efficient charging of tRNA(Val) with valine and preventing formation of mischarged Thr-tRNA(Val) as well as efficient growth of E. coli in vivo. We suggest that the critical role of the proline triplet for ValS activity may explain why bacterial cells coevolved the EF-P rescue system.
Febs Letters, 1983
Two large proteolytic fragments of Escherichia coli 50 S ribosomal subunit protein L16 were gener... more Two large proteolytic fragments of Escherichia coli 50 S ribosomal subunit protein L16 were generated by limited hydrolysis with chymotrypsin (missing 9 N-terminal amino acids) and trypsin (missing 16 Nterminal amino acids). It was found that while intact L16 and its chymotryptic fragment both interact with tRNA (Kd = 5.4 x lo-' M), the tryptic fragment does not. These results are interpreted in terms of possible significance of the residues lo-16 in the peptidyl transferase activity.