Linked Life Data

16849371

Source:http://linkedlifedata.com/resource/pubmed/id/16849371

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2006-8-15
pubmed:abstractText
The ND1 subunit gene of the mitochondrial NADH-ubiquinone oxidoreductase (complex I) is a hot spot for mutations causing Leber hereditary optic neuropathy and several mutations causing the mitochondrial encephalopathy, lactic acidosis and stroke-like episodes syndrome (MELAS). We have used Escherichia coli and Paracoccus denitrificans as model systems to study the effect of mutations 3946 and 3949, which change conserved residues in ND1 and cause MELAS. The vicinity of these mutations was also explored with a series of mutations in charged residues. The 3946 mutation results in E214K substitution in human ND1. Replacement of the equivalent residue in E. coli with lysine or glutamine detracted from enzyme assembly and the assembled enzyme was inactive. However, the equivalent E234Q mutant enzyme in P. denitrificans failed to assemble completely (or was rapidly degraded). Also the corresponding substitution with aspartate decreased the enzyme activity in P. denitrificans and E. coli. The 3949-equivalent substitution, Y229H in E. coli, lowered the catalytic activity by 30%. In addition, an activation of the enzyme during catalytic turnover was seen in this bacterial NDH-1, something that was even more pronounced in another mutant in the same loop, D213E. Several other mutations in this region decreased the enzyme activity. The studied MELAS mutations are situated in a matrix-side loop, which appears to be highly sensitive to structural perturbations. The results provide new information on the function of the region affected by the MELAS mutations 3946 and 3949 that is not obtainable from patient samples or current eukaryote models.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0964-6906
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2543-52
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
The MELAS mutations 3946 and 3949 perturb the critical structure in a conserved loop of the ND1 subunit of mitochondrial complex I.
pubmed:affiliation
Department of Medical Biochemistry and Molecular Biology, University of Oulu, and Clinical Research Center, Oulu University Hospital, Finland.
pubmed:publicationType
Journal Article