Linked Life Data

7559417

Source:http://linkedlifedata.com/resource/pubmed/id/7559417

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
39
pubmed:dateCreated
1995-11-6
pubmed:abstractText
Heme lyases are components of the mitochondrial intermembrane space facilitating the covalent attachment of heme to the apoforms of c-type cytochromes. The precursors of heme lyases are synthesized in the cytosol without the typical N-terminal mitochondrial targeting signal. Here, we have analyzed the mode of import and folding of the two heme lyases of the yeast Saccharomyces cerevisiae, namely of cytochrome c heme lyase and of cytochrome c1 heme lyase. For transport into mitochondria, both proteins use the general protein import machinery of the outer membrane. Import occurred independently of a membrane potential, delta psi, across the inner membrane and ATP in the matrix space, suggesting that the inner membrane is not required for transport along this direct sorting pathway. The presence of a large folded domain in heme lyases was utilized to study their folding in the intermembrane space. Formation of this domain occurred at the same rate as import, indicating that heme lyases fold either during or immediately after their transfer across the membrane. Folding was not affected by depletion of ATP and delta psi or by inhibitors of peptidylprolyl cis-trans isomerases, i.e. it does not involve homologs of known folding factors (like Hsp60 and Hsp70). The energy derived from folding cannot be regarded as a major driving force for import, since the folded domain could be imported into mitochondria with the same efficiency as the intact protein. We conclude that protein folding in the intermembrane space obeys principles different from those established for other subcellular compartments.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
22842-9
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Biogenesis of mitochondrial heme lyases in yeast. Import and folding in the intermembrane space.
pubmed:affiliation
Institut für Physiologische Chemie, Physikalische Biochemie und Zellbiologie, Universität München, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't