Linked Life Data

16513644

Source:http://linkedlifedata.com/resource/pubmed/id/16513644

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
2006-5-1
pubmed:databankReference
pubmed:abstractText
The enzyme prephenate dehydrogenase catalyzes the oxidative decarboxylation of prephenate to 4-hydroxyphenylpyruvate for the biosynthesis of tyrosine. Prephenate dehydrogenases exist as either monofunctional or bifunctional enzymes. The bifunctional enzymes are diverse, since the prephenate dehydrogenase domain is associated with other enzymes, such as chorismate mutase and 3-phosphoskimate 1-carboxyvinyltransferase. We report the first crystal structure of a monofunctional prephenate dehydrogenase enzyme from the hyper-thermophile Aquifex aeolicus in complex with NAD+. This protein consists of two structural domains, a modified nucleotide-binding domain and a novel helical prephenate binding domain. The active site of prephenate dehydrogenase is formed at the domain interface and is shared between the subunits of the dimer. We infer from the structure that access to the active site is regulated via a gated mechanism, which is modulated by an ionic network involving a conserved arginine, Arg250. In addition, the crystal structure reveals for the first time the positions of a number of key catalytic residues and the identity of other active site residues that may participate in the reaction mechanism; these residues include Ser126 and Lys246 and the catalytic histidine, His147. Analysis of the structure further reveals that two secondary structure elements, beta3 and beta7, are missing in the prephenate dehydrogenase domain of the bifunctional chorismate mutase-prephenate dehydrogenase enzymes. This observation suggests that the two functional domains of chorismate mutase-prephenate dehydrogenase are interdependent and explains why these domains cannot be separated.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12919-28
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Crystal structure of prephenate dehydrogenase from Aquifex aeolicus. Insights into the catalytic mechanism.
pubmed:affiliation
Department of Botany, University of Toronto, Toronto, Ontario M5S 3B2, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't