Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.6.5.3 (
complex I
)
8,901
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The 13.2-kDa subunit of
NADH:ubiquinone oxidoreductase
has been shown to be an integral part of the bovine iron-sulfur (IP) part of the protein. This subunit has been shown to interact with at least two other protein subunits of the IP fragment. The amino acid (aa) sequence of this subunit, determined from an acid extract of rat heart was used to generate an oligodeoxyribonucleotide probe which allowed isolation of a cDNA coding for the rat homologue of 13.2-kDa IP. The cDNA was used as a probe of a rat genomic DNA library and two clones were isolated, one of which contained the entire coding region for 13.2-kDa IP. Southern analysis indicates that the IP13 sequence exists as a single copy gene. The sequence of the
genomic clone
contains one intron and promoter elements including a TATAAA region. The 5' flank region has several potential regulatory sites, most notably regions similar to the nuclear respiratory factor 1 (NRF-1) motif, found in other genes which code for mitochondrial proteins [Evans and Scarpulla, Genes Dev. 4 (1990) 1023-1034]. The core domain of the deduced rat aa sequence has a high degree of identity with the mouse and cow homologues of this protein. The high degree of conservation of this protein indicates that the protein is essential for the function of
complex I
.
...
PMID:Genomic sequence, structural organization and evolutionary conservation of the 13.2-kDa subunit of rat NADH:ubiquinone oxidoreductase. 760 54
A 21.3-kDa subunit of the peripheral arm of
complex I
from Neurospora is encoded by a single chromosomal gene, nuo-21.3b. It is located on linkage group V of the fungal genome, linked to inl. We have isolated and characterized a
genomic clone
containing this nuclear gene. A DNA fragment containing a portion of the coding region of the gene and upstream flanking sequences was introduced by transformation into a wild-type strain of Neurospora crassa. A single copy transformant was selected and crossed with another strain, leading to inactivation of nuo-21.3b through repeat-induced point mutations. We have analyzed random progeny from this cross and isolated two mutant strains lacking the 21.3-kDa subunit of
complex I
. One of them was further characterized. Our results suggest that most, if not all, other subunits of
complex I
are present in the mitochondria of the mutant and assembled in a structure similar to
complex I
, representing delta 25% of the amounts of enzyme found in the wild type. Nevertheless, a major intermediate, containing proteins of the peripheral arm of
complex I
, accumulates in the mutant mitochondria. This indicates that the absence of the 21.3-kDa polypeptide results in a disturbed assembly of the enzyme complex, suggesting a role for this polypeptide. We observed similar rates of rotenone-sensitive NADH:ubiquinone oxido-reductase activity in mitochondrial membranes from the mutant and wild-type strains and discuss the possibility that this electron transfer is independent of the more hydrophobic part of
complex I
. Transformation of the mutant with the intact gene and flanking sequences restored the wild-type phenotype.
...
PMID:Disruption of the gene coding for the 21.3-kDa subunit of the peripheral arm of complex I from Neurospora crassa. 812 4
