Linked Life Data

2141652

Source:http://linkedlifedata.com/resource/pubmed/id/2141652

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1990-8-1
pubmed:abstractText
NADH:ubiquinone reductase, the respiratory chain complex I of mitochondria, consists of some 25 nuclear-encoded and seven mitochondrially encoded subunits, and contains as redox groups one FMN, probably one internal ubiquinone and at least four iron-sulphur clusters. We are studying the assembly of the enzyme in Neurospora crassa. The flux of radioactivity in cells that were pulse-labelled with [35S]methionine was followed through immunoprecipitable assembly intermediates into the holoenzyme. Labelled polypeptides were observed to accumulate transiently in a Mr 350,000 intermediate complex. This complex contains all mitochondrially encoded subunits of the enzyme as well as subunits encoded in the nucleus that have no homologous counterparts in a small, merely nuclear-encoded form of the NADH:ubiquinone reductase made by Neurospora crassa cells poisoned with chloramphenicol. With regard to their subunit compositions, the assembly intermediate and small NADH:ubiquinone reductase complement each other almost perfectly to give the subunit composition of the large complex I. These results suggest that two pathways exist in the assembly of complex I that independently lead to the preassembly of two major parts, which subsequently join to form the complex. One preassembled part is related to the small form of NADH:ubiquinone reductase and contributes most of the nuclear-encoded subunits, FMN, three iron-sulphur clusters and the site for the internal ubiquinone. The other part is the assembly intermediate and contributes all mitochondrially encoded subunits, one iron-sulphur cluster and the catalytic site for the substrate ubiquinone. We discuss the results with regard to the evolution of the electron pathway through complex I.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
213
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
845-57
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:2141652-Amino Acid Sequence, pubmed-meshheading:2141652-Base Sequence, pubmed-meshheading:2141652-Cell Nucleus, pubmed-meshheading:2141652-Centrifugation, Density Gradient, pubmed-meshheading:2141652-Chromatography, High Pressure Liquid, pubmed-meshheading:2141652-DNA, Fungal, pubmed-meshheading:2141652-DNA, Mitochondrial, pubmed-meshheading:2141652-Genes, Fungal, pubmed-meshheading:2141652-Kinetics, pubmed-meshheading:2141652-Mitochondria, pubmed-meshheading:2141652-Molecular Sequence Data, pubmed-meshheading:2141652-Multienzyme Complexes, pubmed-meshheading:2141652-NAD, pubmed-meshheading:2141652-NAD(P)H Dehydrogenase (Quinone), pubmed-meshheading:2141652-Neurospora, pubmed-meshheading:2141652-Neurospora crassa, pubmed-meshheading:2141652-Precipitin Tests, pubmed-meshheading:2141652-Protein Biosynthesis, pubmed-meshheading:2141652-Quinone Reductases
pubmed:year
1990
pubmed:articleTitle
Assembly of NADH: ubiquinone reductase (complex I) in Neurospora mitochondria. Independent pathways of nuclear-encoded and mitochondrially encoded subunits.
pubmed:affiliation
Universität Düsseldorf, Institut für Biochemie, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't