Skatebro:Notes Papers

From OpenWetWare

(Difference between revisions)
Jump to: navigation, search
(New page: ==SsrA-mediated tagging and proteolysis of LacI and its role in the regulation of lac operon== *SsrA RNA (also known as 10sRNA or tmRNA) acts as both mRNA and tRNA when ribosomes are pause...)
Current revision (06:22, 9 February 2008) (view source)
(Removing all content from page)
 
Line 1: Line 1:
-
==SsrA-mediated tagging and proteolysis of LacI and its role in the regulation of lac operon==
 
-
*SsrA RNA (also known as 10sRNA or tmRNA) acts as both mRNA and tRNA when ribosomes are paused at 3’ end of an mRNA lacking a stop codon.
 
-
*Trans-translation process (mediated by SsrA RNA) leads to addition of C-term tag to polypeptide. Tagged peptide is then degraded by specific proteases.
 
-
*Major biological relevance of SsrA-mediated tagging and proteolysis is believed to be in providing both a way to clear the ribosome stalled on mRNAs and a quality-control mechanism that allows cell to eliminate potentially harmful truncated polypeptides.
 
-
*For example: the binding of LacI to the lac operators results in truncated lacI mRNAs that are tagged/degraded by the SsrA trans-translation system. (note: in presence of IPTG, IPTG binds LacI repressor s.t. LacI repressor doesn’t bind operators and LacI mRNAs are not truncated or tagged/degraded)
 
-
==Micros for microbes: non-coding regulatory RNAs in bacteria==
 
-
*small non-coding RNAs with important regulatory roles are not confined to eukaryotes
 
-
*they act post-transcriptionally, imposing a regulatory step that is independent of and epistatic to transcriptional signals.
 
-
*they act by base-pairing with target mRNAs, resulting in changes in the translation and stability of the mRNA.
 

Current revision

Personal tools