Linked Life Data

15182181

Source:http://linkedlifedata.com/resource/pubmed/id/15182181

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
2004-6-8
pubmed:abstractText
Human mitochondrial malic enzyme is a regulatory enzyme with ATP as an inhibitor. Structural studies reveal that the enzyme has two ATP-binding sites, one at the NAD(+)-binding site in the active center and the other at the exo site in the tetramer interface. Inhibition of the enzyme activity is due to the competition between ATP and NAD(+) for the nucleotide-binding site at the active center with an inhibition constant of 81 microM. Binding of the ATP molecule at the exo site, on the other hand, is important for the maintenance of the quaternary structural integrity. The enzyme exists in solution at neutral pH and at equilibrium of the dimer and tetramer with a dissociation constant (K(TD)) of 0.67 microM. ATP, at a physiological concentration, shifts the equilibrium toward tetramer and decreases the K(TD) by many orders of magnitude. Mutation of a single residue Arg542 at the tetrameric interfacial exo site resulted in dimeric mutants. ATP thus has dual functional roles in the mitochondrial malic enzyme.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7382-90
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Dual functional roles of ATP in the human mitochondrial malic enzyme.
pubmed:affiliation
Faculty of Life Sciences, Institute of Biochemistry, Structure Biology Program, and Proteome Research Center, National Yang-Ming University, Taipei 112, Taiwan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't