Linked Life Data

21799029

Source:http://linkedlifedata.com/resource/pubmed/id/21799029

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2011-8-18
pubmed:abstractText
The 3'-untranslated region (UTR) of the group 2 coronavirus mouse hepatitis virus (MHV) genome contains a predicted bulged stem-loop (designated P0ab), a conserved cis-acting pseudoknot (PK), and a more distal stem-loop (designated P2). Base-pairing to create the pseudoknot-forming stem (P1(pk)) is mutually exclusive with formation of stem P0a at the base of the bulged stem-loop; as a result, the two structures cannot be present simultaneously. Herein, we use thermodynamic methods to evaluate the ability of individual subdomains of the 3' UTR to adopt a pseudoknotted conformation. We find that an RNA capable of forming only the predicted PK (58 nt; 3' nucleotides 241-185) adopts the P2 stem-loop with little evidence for P1(pk) pairing in 0.1 M KCl and the absence of Mg(2+); as Mg(2+) or 1 M KCl is added, a new thermal unfolding transition is induced and assignable to P1(pk) pairing. The P1(pk) helix is only marginally stable, ?G(25) ? 1.2 ± 0.3 kcal/mol (5.0 mM Mg(2+), 100 mM K(+)), and unfolded at 37°C. Similar findings characterize an RNA 5' extended through the P0b helix only (89 nt; 294-185). In contrast, an RNA capable of forming either the P0a helix or the pseudoknot (97 nt; 301-185) forms no P1(pk) helix. Thermal unfolding simulations are fully consistent with these experimental findings. These data reveal that the PK forms weakly and only when the competing double-hairpin structure cannot form; in the UTR RNA, the double hairpin is the predominant conformer under all solution conditions.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1469-9001
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1747-59
pubmed:dateRevised
2011-11-4
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
A conserved RNA pseudoknot in a putative molecular switch domain of the 3'-untranslated region of coronaviruses is only marginally stable.
pubmed:affiliation
Department of Chemistry, Texas A&M University, College Station, Texas 77843-2128, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural