Chan NC and Lithgow T (2008) The peripheral membrane subunits of the SAM complex function codependently in mitochondrial outer membrane biogenesis. Mol Biol Cell 19(1):126-36
Abstract: The sorting and assembly machinery (SAM) complex functions in the assembly of beta-barrel proteins into the mitochondrial outer membrane. It is related to the Omp85/YaeT machinery in bacterial outer membranes, but the eukaryotic SAM complex is distinguished by two peripheral subunits, Sam37 and Sam35, that sit on the cytosolic face of the complex. The function of these subunits in beta-barrel protein assembly is currently unclear. By screening a library of sam35 mutants, we show that 13 distinct alleles were each specifically suppressed by overexpression of SAM37. Two of these mutants, sam35-409 and sam35-424, show distinct phenotypes that enable us to distinguish the function of Sam35 from that of Sam37. Sam35 is required for the SAM complex to bind outer membrane substrate proteins: destabilization of Sam35 inhibits substrate binding by Sam50. Sam37 acts later than Sam35, apparently to assist release of substrates from the SAM complex. Very different environments surround bacteria and mitochondria, and we discuss the role of Sam35 and Sam37 in terms of the problems peculiar to mitochondrial protein substrates.
|Status: Published||Type: Journal Article | Research Support, Non-U.S. Gov't||PubMed ID: 17978093|
Topics addressed in this paper
Number of different genes curated to this paper: 4
- To find other papers on a gene and topic, click on the colored ball in the appropriate box.
- displays other papers with information about that topic for that gene.
- displays other papers in SGD that are associated with that topic.
The topic is addressed in these papers but does not describe a specific gene or chromosomal feature.
- To go to the Locus page for a gene, click on the gene name.