These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Structure and evolution of mitochondrial outer membrane proteins of beta-barrel topology.
    Author: Zeth K.
    Journal: Biochim Biophys Acta; 2010; 1797(6-7):1292-9. PubMed ID: 20450883.
    Abstract:
    Gram-negative bacteria are the ancestors of mitochondrial organelles. Consequently, both entities contain two surrounding lipid bilayers known as the inner and outer membranes. While protein synthesis in bacteria is accomplished in the cytoplasm, mitochondria import 90-99% of their protein ensemble from the cytosol in the opposite direction. Three protein families including Sam50, VDAC and Tom40 together with Mdm10 compose the set of integral beta-barrel proteins embedded in the mitochondrial outer membrane in S. cerevisiae (MOM). The 16-stranded Sam50 protein forms part of the sorting and assembly machinery (SAM) and shows a clear evolutionary relationship to members of the bacterial Omp85 family. By contrast, the evolution of VDAC and Tom40, both adopting the same fold cannot be traced to any bacterial precursor. This finding is in agreement with the specific function of Tom40 in the TOM complex not existent in the enslaved bacterial precursor cell. Models of Tom40 and Sam50 have been developed using X-ray structures of related proteins. These models are analyzed with respect to properties such as conservation and charge distribution yielding features related to their individual functions.
    [Abstract] [Full Text] [Related] [New Search]