Linked Life Data

11934893

Source:http://linkedlifedata.com/resource/pubmed/id/11934893

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
2002-6-10
pubmed:abstractText
Genetic evidence has indicated that Isc proteins play an important role in iron-sulfur cluster biogenesis. In particular, IscU is believed to serve as a scaffold for the assembly of a nascent iron-sulfur cluster that is subsequently delivered to target iron-sulfur apoproteins. We report the characterization of an IscU from Thermatoga maritima, an evolutionarily ancient hyperthermophilic bacterium. The stabilizing influence of a D40A substitution allowed characterization of the holoprotein. Mössbauer (delta = 0.29 +/- 0.03 mm/s, DeltaE(Q) = 0.58 +/- 0.03 mm/s), UV-visible absorption, and circular dichroism studies of the D40A protein show that T. maritima IscU coordinates a [2Fe-2S]2+ cluster. Thermal denaturation experiments demonstrate that T. maritima IscU is a thermally stable protein with a thermally unstable cluster. This is also the first IscU type domain that is demonstrated to possess a high degree of secondary and tertiary structure. CD spectra indicate 36.7% alpha-helix, 13.1% antiparallel beta-sheet, 11.3% parallel beta-sheet, 20.2% beta-turn, and 19.1% other at 20 degrees C, with negligible spectral change observed at 70 degrees C. Cluster coordination also has no effect on the secondary structure of the protein. The dispersion of signals in 1H-15N heteronuclear single quantum correlation NMR spectra of wild type and D40A IscU supports the presence of significant tertiary structure for the apoprotein, consistent with a scaffolding role, and is in marked contrast to other low molecular weight Fe-S proteins where cofactor coordination is found to be necessary for proper protein folding. Consistent with the observed sequence homology and proposed conservation of function for IscU-type proteins, we demonstrate T. maritima IscU-mediated reconstitution of human apoferredoxin.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21397-404
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:11934893-Amino Acid Sequence, pubmed-meshheading:11934893-Bacterial Proteins, pubmed-meshheading:11934893-Chromatography, Gel, pubmed-meshheading:11934893-Circular Dichroism, pubmed-meshheading:11934893-Cloning, Molecular, pubmed-meshheading:11934893-DNA, pubmed-meshheading:11934893-Electron Spin Resonance Spectroscopy, pubmed-meshheading:11934893-Escherichia coli Proteins, pubmed-meshheading:11934893-Ferredoxins, pubmed-meshheading:11934893-Humans, pubmed-meshheading:11934893-Iron-Sulfur Proteins, pubmed-meshheading:11934893-Kinetics, pubmed-meshheading:11934893-Magnetic Resonance Spectroscopy, pubmed-meshheading:11934893-Mass Spectrometry, pubmed-meshheading:11934893-Molecular Sequence Data, pubmed-meshheading:11934893-Mutagenesis, Site-Directed, pubmed-meshheading:11934893-Protein Folding, pubmed-meshheading:11934893-Protein Structure, Secondary, pubmed-meshheading:11934893-Protein Structure, Tertiary, pubmed-meshheading:11934893-Sequence Homology, Amino Acid, pubmed-meshheading:11934893-Temperature, pubmed-meshheading:11934893-Thermodynamics, pubmed-meshheading:11934893-Thermotoga maritima, pubmed-meshheading:11934893-Ultraviolet Rays
pubmed:year
2002
pubmed:articleTitle
Iron-sulfur cluster biosynthesis. Thermatoga maritima IscU is a structured iron-sulfur cluster assembly protein.
pubmed:affiliation
Evans Laboratory of Chemistry, Ohio State University, Columbus, Ohio 43210, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't