The pathway of membrane insertion and assembly of a signal anchor sequence specific for the outer mitochondrial membrane has been investigated. Signal anchor protein insertion into the outer membrane, in vitro, was found to overlap with a general import pathway followed by the outer membrane protein, porin, as well as matrix-targeted proteins. However, signal anchor protein insertion did not require a postreceptor import step involved in porin insertion and matrix protein translocation. Also, in contrast to the membrane insertion of porin, signal anchor protein insertion did not require nucleoside triphosphates for transfer of bound precursor to the membrane assembled form. Following outer membrane integration, a hybrid protein containing the signal anchor sequence of yeast Tom70 was found to assemble into homodimers. Dimerization was mediated by the transmembrane domain. A sequence motif containing alanine residues clustered on one face of the predicted membrane-spanning $ alpha$-helix was important for dimerization, perhaps allowing favourable close packing of the transmembrane helices.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.42046 |
| Date | January 1996 |
| Creators | Millar, Douglas G. |
| Contributors | Shore, Gordon C. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Biochemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001548850, proquestno: NQ29951, Theses scanned by UMI/ProQuest. |
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