Linked Life Data

16939278

Source:http://linkedlifedata.com/resource/pubmed/id/16939278

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
35
pubmed:dateCreated
2006-8-30
pubmed:abstractText
Isopentenyl diphosphate isomerase (IDI) catalyzes the essential conversion of isopentenyl diphosphate (IPP) to dimethylallyl diphosphate (DMAPP) in the mevalonate entry into the isoprenoid biosynthetic pathway. Two convergently evolved forms of IDI are known. Type I IDI, which is found in Eukarya and many Bacteria, catalyzes the isomerization of IPP and DMAPP by a protonation-deprotonation mechanism. The enzyme requires two divalent metal ions for activity. An X-ray structure of type I IDI from crystals soaked with (N,N-dimethylamino)-1-ethyl diphosphate (NIPP), a potent transition-state analogue for the carbocationic intermediate in the isomerization reaction, shows one of the metals in a His(3)Glu(2) hexacoordinate binding site, while the other forms a bridge between the diphosphate moiety of the substrate and the enzyme (Wouters, J.; et al. J. Biol. Chem. 2003, 278, 11903). Reconstitution of metal-free recombinant Escherichia coli type I IDI with several divalent metals-Mg(2+), Mn(2+), Zn(2+), Co(2+), Ni(2+), and Cd(2+)-generated active enzyme. Freshly purified IDI contained substoichiometric levels of a single metal ion, presumably bound in the hexacoordinate site. When NIPP was added to the disruption and purification buffers of enzyme, the purified protein contained 0.72 equiv of Mg(2+), 0.92 equiv of Zn(2+), and 0.10 equiv of Mn(2+). These results are consistent with a structure in which Mg(2+) facilitates diphosphate binding and Zn(2+) or Mn(2+) occupies the hexacoordinate site.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
128
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11545-50
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Escherichia coli type I isopentenyl diphosphate isomerase: structural and catalytic roles for divalent metals.
pubmed:affiliation
Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural