東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Initiation of RNA decay in Escherich...

Celesnik, Helena Sabina.

Linked to FindBook

Google Book

Amazon

博客來

Initiation of RNA decay in Escherichia coli by 5' pyrophosphate removal.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	Initiation of RNA decay in Escherichia coli by 5' pyrophosphate removal./
Author:	Celesnik, Helena Sabina.
Description:	151 p.
Notes:	Adviser: Joel G. Belasco.
Contained By:	Dissertation Abstracts International68-01B.
Subject:	Biology, Cell. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3247353

Initiation of RNA decay in Escherichia coli by 5' pyrophosphate removal.
Celesnik, Helena Sabina.

Initiation of RNA decay in Escherichia coli by 5' pyrophosphate removal. - 151 p.

Adviser: Joel G. Belasco.

Thesis (Ph.D.)--New York University, 2007.

RNA degradation is an important process required for controlling expression of genes in all organisms. In prokaryotes, it has long been thought that internal cleavage by an endonuclease is the initial, rate-determining step in mRNA decay. However, this assumption fails to explain the influence of 5' termini on the half-lives of primary transcripts. We investigated the initial events of RNA degradation in Escherichia coil. By using a novel assay to examine the 5' phosphorylation state of RNA and a self-cleaving hammerhead ribozyme to study the degradative consequences of an unphosphorylated 5' end, we have identified a previously unrecognized prior step in decay that triggers subsequent internal cleavage by the endonuclease RNase E and thereby governs RNA longevity: the rate-determining conversion of a triphosphorylated to a monophosphorylated 5' terminus. As RNase E is known to cleave 5' monophosphorylated RNAs much faster than their triphosphorylated counterparts, our finding that pyrophosphate is removed from the 5' end of mRNA now explains how unpaired 5'-terminal nucleotides on primary transcripts can aid access to internal cleavage sites, as the catalytic activation of RNase E by a 5' monophosphate requires a single-stranded 5' terminus. Previously the 5'-end dependence of RNase E had only been thought to explain the comparative instability of 3'-terminal cleavage products. The findings presented here overturn the accepted model for bacterial mRNA degradation in bacteria and reveal a striking parallel between mechanisms of RNA degradation in prokaryotes and eukaryotes, which were previously thought to be distinct.Subjects--Topical Terms:

1017686
Biology, Cell.

Initiation of RNA decay in Escherichia coli by 5' pyrophosphate removal.
LDR:02511nam 2200277 a 45 001 964126
005 20110901
008 110901s2007 eng d
035 $a (UMI)AAI3247353
035 $a AAI3247353
040 $a UMI $c UMI
100 1 $a Celesnik, Helena Sabina. $3 1287194
245 1 0 $a Initiation of RNA decay in Escherichia coli by 5' pyrophosphate removal.
300 $a 151 p.
500 $a Adviser: Joel G. Belasco.
500 $a Source: Dissertation Abstracts International, Volume: 68-01, Section: B, page: 0070.
502 $a Thesis (Ph.D.)--New York University, 2007.
520 $a RNA degradation is an important process required for controlling expression of genes in all organisms. In prokaryotes, it has long been thought that internal cleavage by an endonuclease is the initial, rate-determining step in mRNA decay. However, this assumption fails to explain the influence of 5' termini on the half-lives of primary transcripts. We investigated the initial events of RNA degradation in Escherichia coil. By using a novel assay to examine the 5' phosphorylation state of RNA and a self-cleaving hammerhead ribozyme to study the degradative consequences of an unphosphorylated 5' end, we have identified a previously unrecognized prior step in decay that triggers subsequent internal cleavage by the endonuclease RNase E and thereby governs RNA longevity: the rate-determining conversion of a triphosphorylated to a monophosphorylated 5' terminus. As RNase E is known to cleave 5' monophosphorylated RNAs much faster than their triphosphorylated counterparts, our finding that pyrophosphate is removed from the 5' end of mRNA now explains how unpaired 5'-terminal nucleotides on primary transcripts can aid access to internal cleavage sites, as the catalytic activation of RNase E by a 5' monophosphate requires a single-stranded 5' terminus. Previously the 5'-end dependence of RNase E had only been thought to explain the comparative instability of 3'-terminal cleavage products. The findings presented here overturn the accepted model for bacterial mRNA degradation in bacteria and reveal a striking parallel between mechanisms of RNA degradation in prokaryotes and eukaryotes, which were previously thought to be distinct.
590 $a School code: 0146.
650 4 $a Biology, Cell. $3 1017686
650 4 $a Biology, Microbiology. $3 1017734
650 4 $a Chemistry, Biochemistry. $3 1017722
690 $a 0379
690 $a 0410
690 $a 0487
710 2 0 $a New York University. $3 515735
773 0 $t Dissertation Abstracts International $g 68-01B.
790 $a 0146
790 1 0 $a Belasco, Joel G., $e advisor
791 $a Ph.D.
792 $a 2007
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3247353