Mitochondrial protein-import machinery: correlating structure with function.
Most mitochondrial proteins are synthesized in the cytosol, translocated into the organelle and directed along specific sorting pathways. Over the past 20 years, >30 proteins have been identified as having key roles in mitochondrial protein import. Recently, the elucidation of the structures of several import components has provided fresh insight into the import process. Here, we review the different pathways involved in sorting proteins into mitochondrial subcompartments. Along the way, we highlight the available structural information about the protein-import machinery and discuss how these structures correlate with previously ascribed functions. Future challenges for the cell biologists will be to use this structural information to test specific hypotheses addressing the molecular mechanisms of mitochondrial protein import.
Baker
Michael J
MJ
Department of Biochemistry, La Trobe University, Melbourne 3086, Australia.
Frazier
Ann E
AE
Gulbis
Jacqueline M
JM
Ryan
Michael T
MT
D000818:Animals; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D026901:Membrane Transport Proteins; D008928:Mitochondria / Q000378:metabolism* / Q000648:ultrastructure; D033681:Mitochondrial Membrane Transport Proteins / Q000737:chemistry / Q000378:metabolism*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000378:metabolism; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000378:metabolism; D046912:Multiprotein Complexes; D011487:Protein Conformation; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology*; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism