Linked Life Data

9383162

Source:http://linkedlifedata.com/resource/pubmed/id/9383162

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-2-19
pubmed:abstractText
The Escherichia coli degradosome is a multienzyme complex with four major protein components: the endoribonuclease RNase E, the exoribonuclease PNPase, the RNA helicase RhlB and enolase. The first three of these proteins are known to have important functions in mRNA processing and degradation. In this work, we identify an additional component of the degradosome, polyphosphate kinase (PPK), which catalyses the reversible polymerization of the gamma-phosphate of ATP into polyphosphate (poly(P)). An E. coli strain deleted for the ppk gene showed increased stability of the ompA mRNA. Purified His-tagged PPK was shown to bind RNA, and RNA binding was prevented by hydrolysable ATP. Chemical modification of RNA by PPK, for example the addition or removal of 3' or 5' terminal phosphates, could not be detected. However, polyphosphate was found to inhibit RNA degradation by the degradosome in vitro. This inhibition was overcome by the addition of ADP, required for the degradation of polyphosphate and for the regeneration of ATP by PPK in the degradosome. Thus, PPK in the degradosome appears to maintain an appropriate microenvironment, removing inhibitory polyphosphate and NDPs and regenerating ATP.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
387-98
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Polyphosphate kinase is a component of the Escherichia coli RNA degradosome.
pubmed:affiliation
Nuffield Department of Clinical Biochemistry, Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't