Linked Life Data

14580215

Source:http://linkedlifedata.com/resource/pubmed/id/14580215

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
43
pubmed:dateCreated
2003-10-28
pubmed:abstractText
Phosphofructokinase from Escherichia coli (EcPFK) is a homotetramer with four active sites, which bind the substrates fructose-6-phosphate (Fru-6-P) and MgATP. In the presence of low concentrations of Fru-6-P, MgATP displays substrate inhibition. Previous proposals to explain this substrate inhibition have included both kinetic and allosteric mechanisms. We have isolated hybrid tetramers containing one wild type subunit and three mutated subunits (1:3). The mutated subunits contain mutations that decrease affinity for Fru-6-P (R243E) or MgATP (F76A/R77D/R82A) allowing us to systematically simplify the possible allosteric interactions between the two substrates. In the absence of a rate equation to explain the allosteric effects in a tetramer, the data have been compared to simulated data for an allosteric dimer. Since the apparent substrate inhibition caused by MgATP binding is not seen in hybrid tetramers with only a single native MgATP binding site, the proposed kinetic mechanism is not able to explain this phenomenon. The data presented are consistent with an allosteric antagonism between MgATP in one active site and Fru-6-P in a second active site.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12676-81
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Mechanism of substrate inhibition in Escherichia coli phosphofructokinase.
pubmed:affiliation
Department of Biochemistry and Biophysics and the Center for Advanced Biomolecular Research, Texas A&M University, 2128 TAMU, College Station, Texas 77843-2128, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't