PMID:11470925: Difference between revisions
Edited by wikibot |
imported>Wikientrybot change PMID template to TableEdit version |
||
| (6 intermediate revisions by 2 users not shown) | |||
| Line 1: | Line 1: | ||
{{RightTOC}} | {{RightTOC}} | ||
<!--box uid=d41d8cd98f00b204e9800998ecf8427e.119870.Q52238187a1347--> | |||
<!-- | |||
****************************************************************************************** | |||
* | |||
* ** PLEASE DON'T EDIT THIS TABLE DIRECTLY. Use the edit table link under the table. ** | |||
* | |||
****************************************************************************************** --> | |||
{| id="Q52238187a1347" class=" tableEdit PMID_info_table" | |||
|- | |- | ||
| | !align=left |Citation | ||
|| | |||
'''Gong, F, Ito, K, Nakamura, Y and Yanofsky, C''' (2001) The mechanism of tryptophan induction of tryptophanase operon expression: tryptophan inhibits release factor-mediated cleavage of TnaC-peptidyl-tRNA(Pro). ''Proc. Natl. Acad. Sci. U.S.A.'' '''98''':8997-9001 | |||
|- | |||
!align=left |Abstract | |||
|| | |||
Expression of the tryptophanase (tna) operon of Escherichia coli is regulated by catabolite repression and tryptophan-induced transcription antitermination. In a previous study, we reproduced the regulatory features of this operon observed in vivo by using an in vitro S-30 system. We also found that, under inducing conditions, the leader peptidyl-tRNA (TnaC-peptidyl-tRNA(Pro)) is not cleaved; it accumulates in the S-30 reaction mixture. In this paper, we examine the requirements for TnaC-peptidyl-tRNA(Pro) accumulation and cleavage, in vitro. We show that this peptidyl-tRNA remains bound to the translating ribosome. Removal of free tryptophan and addition of release factor 1 or 2 leads to hydrolysis of TnaC-peptidyl-tRNA(Pro) and release of TnaC from the ribosome-mRNA complex. Release factor-mediated cleavage is prevented by the addition of tryptophan. TnaC of the ribosome-bound TnaC-peptidyl-tRNA(Pro) was transferable to puromycin. This transfer was also blocked by tryptophan. Tests with various tryptophan analogs as substitutes for tryptophan revealed the existence of strict structural requirements for tryptophan action. Our findings demonstrate that the addition of tryptophan to ribosomes bearing nascent TnaC-peptidyl-tRNA(Pro) inhibits both TnaC peptidyl-tRNA(Pro) hydrolysis and TnaC peptidyl transfer. The associated translating ribosome therefore remains attached to the leader transcript where it blocks Rho factor binding and subsequent transcription termination. | |||
|- | |||
!align=left |Links | |||
|| | |||
[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11470925 PubMed] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC55362 PMC55362] | |||
Online version:[http://dx.doi.org/10.1073/pnas.171299298 10.1073/pnas.171299298] | |||
|- | |- | ||
|{{ | !align=left |Keywords | ||
|| | |||
Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Escherichia coli Proteins; Hydrolysis; Operon; Puromycin/antagonists & inhibitors; RNA, Transfer, Amino Acyl/metabolism; RNA, Transfer, Pro/metabolism; Tryptophan/physiology; Tryptophanase/genetics | |||
|- class="tableEdit_footer" | |||
|<span class="tableEdit_editLink plainlinks">[{{SERVER}}{{SCRIPTPATH}}?title=Special:TableEdit&id=d41d8cd98f00b204e9800998ecf8427e.119870.Q52238187a1347&page=119870&pagename={{FULLPAGENAMEE}}&type=1&template=PMID_info_table edit table]</span> || | |||
|} | |} | ||
<!--box uid=d41d8cd98f00b204e9800998ecf8427e.119870.Q52238187a1347--> | |||
==Significance {{HelpIcon|Help:Literature}} == | ==Significance {{HelpIcon|Help:Literature}} == | ||
{{LitSignificance}} | {{LitSignificance}} | ||
| Line 19: | Line 38: | ||
==Annotations {{HelpIcon|Help:Literature}}== | ==Annotations {{HelpIcon|Help:Literature}}== | ||
< | <annotationlinks/> | ||
==EcoliWiki Links {{HelpIcon|Help:Literature}} == | ==EcoliWiki Links {{HelpIcon|Help:Literature}} == | ||
Latest revision as of 04:15, 15 September 2013
| Citation |
Gong, F, Ito, K, Nakamura, Y and Yanofsky, C (2001) The mechanism of tryptophan induction of tryptophanase operon expression: tryptophan inhibits release factor-mediated cleavage of TnaC-peptidyl-tRNA(Pro). Proc. Natl. Acad. Sci. U.S.A. 98:8997-9001 |
|---|---|
| Abstract |
Expression of the tryptophanase (tna) operon of Escherichia coli is regulated by catabolite repression and tryptophan-induced transcription antitermination. In a previous study, we reproduced the regulatory features of this operon observed in vivo by using an in vitro S-30 system. We also found that, under inducing conditions, the leader peptidyl-tRNA (TnaC-peptidyl-tRNA(Pro)) is not cleaved; it accumulates in the S-30 reaction mixture. In this paper, we examine the requirements for TnaC-peptidyl-tRNA(Pro) accumulation and cleavage, in vitro. We show that this peptidyl-tRNA remains bound to the translating ribosome. Removal of free tryptophan and addition of release factor 1 or 2 leads to hydrolysis of TnaC-peptidyl-tRNA(Pro) and release of TnaC from the ribosome-mRNA complex. Release factor-mediated cleavage is prevented by the addition of tryptophan. TnaC of the ribosome-bound TnaC-peptidyl-tRNA(Pro) was transferable to puromycin. This transfer was also blocked by tryptophan. Tests with various tryptophan analogs as substitutes for tryptophan revealed the existence of strict structural requirements for tryptophan action. Our findings demonstrate that the addition of tryptophan to ribosomes bearing nascent TnaC-peptidyl-tRNA(Pro) inhibits both TnaC peptidyl-tRNA(Pro) hydrolysis and TnaC peptidyl transfer. The associated translating ribosome therefore remains attached to the leader transcript where it blocks Rho factor binding and subsequent transcription termination. |
| Links |
PubMed PMC55362 Online version:10.1073/pnas.171299298 |
| Keywords |
Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Escherichia coli Proteins; Hydrolysis; Operon; Puromycin/antagonists & inhibitors; RNA, Transfer, Amino Acyl/metabolism; RNA, Transfer, Pro/metabolism; Tryptophan/physiology; Tryptophanase/genetics |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.