Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1996-6-24
pubmed:databankReference
pubmed:abstractText
The Neurospora crassa mutants, cyt-5-1 and cyt-5-4 have a cytochrome b- and aa3-deficient phenotype, suggesting that they result from a deficiency in a nuclear-coded component of the mitochondrial gene expression apparatus (Bertrand, H., Nargang, F. E., Colllins, R. A., and Zagozeski, C. A. (1977) Mol. Gen. Genet. 153,247-257). The complementing wild-type gene has been cloned and and shown to encode a protein with significant sequence similarity to Saccharomyces cerevisiae mitochondrial RNA polymerase and bacteriophage RNA polymerases. There are remarkable differences between the N. crassa protein and its yeast homologue, including a region of very little homology near the N termini of the two gene products. The cyt-5 gene encodes a stretch of polyglutamine in this region of uniquesequence. In addition, an acidic insertion (86 amino acids, of which 24 are Asp or Glu and 10 are Arg or Lys) is present near the C terminus of the cyt-5 gene product. Transcript levels of the cytochrome b and cytochrome oxidase subunit III genes are severely reduced in cyt-5 mutants, suggesting a likely mechanism for the cytochrome-deficient phenotype. In contrast, mitochondrial rRNAs accumulate to nearly normal levels in cyt-5 mutants. However, mitochondrial rRNA levels are not indicative of the rate of transcription of the corresponding genes, since crude lysates of mitochondria from cyt-5 mutants exhibit greatly reduced transcriptional activity with a 19 S rRNA promoter. The cyt-5 gene is flanked by at least one gene whose product also may be involved in mitochondrial function.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6537-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8626458-Amino Acid Sequence, pubmed-meshheading:8626458-Cell Nucleus, pubmed-meshheading:8626458-Cloning, Molecular, pubmed-meshheading:8626458-Cytochrome b Group, pubmed-meshheading:8626458-DNA-Directed RNA Polymerases, pubmed-meshheading:8626458-Electron Transport Complex IV, pubmed-meshheading:8626458-Gene Expression, pubmed-meshheading:8626458-Genes, Fungal, pubmed-meshheading:8626458-Genetic Complementation Test, pubmed-meshheading:8626458-Mitochondria, pubmed-meshheading:8626458-Molecular Sequence Data, pubmed-meshheading:8626458-Mutation, pubmed-meshheading:8626458-Neurospora crassa, pubmed-meshheading:8626458-Peptides, pubmed-meshheading:8626458-Phenotype, pubmed-meshheading:8626458-RNA, Fungal, pubmed-meshheading:8626458-Repetitive Sequences, Nucleic Acid, pubmed-meshheading:8626458-Sequence Homology, Amino Acid
pubmed:year
1996
pubmed:articleTitle
Cloning and characterization of the Neurospora crassa cyt-5 gene. A nuclear-coded mitochondrial RNA polymerase with a polyglutamine repeat.
pubmed:affiliation
Department of Biochemistry, Ohio State Biochemistry Program, Ohio State University, Columbus 43210-1292, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.