Linked Life Data

12022880

Source:http://linkedlifedata.com/resource/pubmed/id/12022880

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2002-5-22
pubmed:abstractText
Acireductone dioxygenases (ARDs) are enzymes involved in the methionine recycle pathway, which regulates aspects of the cell cycle. Klebsiella pneumoniae produces two enzymes that share a common polypeptide sequence and differ only in the metal ion present. Reaction of acireductone (1,2-dihydroxy-3-keto-5-methylthiopentene) with Fe-ARD and dioxygen produces formate and 2-keto-4-methylthiobutanoic acid, the alpha-ketoacid precursor of methionine. Ni-ARD reacts with acireductone and dioxygen to produce methylthiopropionate, CO, and formate and does not lie on the methionine recycle pathway. An X-ray absorption spectroscopy (XAS) study of the structure of the catalytic Ni center in resting Ni-ARD enzyme and the enzyme-substrate complex is reported. This study establishes the structure of the Ni site in resting Ni-ARD as containing a six coordinate Ni site composed of O/N-donor ligands including 3-4 histidine residues, demonstrates that the substrate binds to the Ni center in a bidentate fashion by displacing two ligands, at least one of which is a histidine ligand, and provides insight into the mechanism of catalysis employed by a Ni-containing dioxygenase. Efficiently relaxed and hyperfine-shifted resonances are observed in the (1)H nuclear magnetic resonance spectrum of Ni-ARD that can be attributed to the His imidazoles ligating the paramagnetic Ni ion and are consistent with the XAS results regarding His ligation. These resonances show significant perturbation in the presence of substrate, confirming that the metal ion interacts directly with the substrate.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6761-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
XAS investigation of the structure and function of Ni in acireductone dioxygenase.
pubmed:affiliation
Department of Chemistry, Lederle Grasduate Research Center, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003-9336, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't