title: Structural basis for the function of Tim50 in the mitochondrial presequence translocase.
abstract: Many mitochondrial proteins are synthesized as preproteins carrying amino-terminal presequences in the cytosol. The preproteins are imported by the translocase of the outer mitochondrial membrane and the presequence translocase of the inner membrane. Tim50 and Tim23 transfer preproteins through the intermembrane space to the inner membrane. We report the crystal structure of the intermembrane space domain of yeast Tim50 to 1.83 Å resolution. A protruding β-hairpin of Tim50 is crucial for interaction with Tim23, providing a molecular basis for the cooperation of Tim50 and Tim23 in preprotein translocation to the protein-conducting channel of the mitochondrial inner membrane.
authors.affiliation: Department of Cell Biology, University of Alabama at Birmingham, 1918 University Boulevard, Birmingham, AL 35294-0005, USA.
authors.forename: Xinguo
authors.initials: X
authors.lastname: Qian
authors.forename: Michael
authors.initials: M
authors.lastname: Gebert
authors.forename: Jan
authors.initials: J
authors.lastname: Höpker
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.forename: Jingzhi
authors.initials: J
authors.lastname: Li
authors.forename: Nils
authors.initials: N
authors.lastname: Wiedemann
authors.forename: Martin
authors.initials: M
authors.lastname: van der Laan
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Pfanner
authors.forename: Bingdong
authors.initials: B
authors.lastname: Sha
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000378:metabolism; D008928:Mitochondria; D033681:Mitochondrial Membrane Transport Proteins / Q000737:chemistry* / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000378:metabolism; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000378:metabolism; D010458:Peptidyl Transferases / Q000737:chemistry / Q000378:metabolism; D011498:Protein Precursors / Q000032:analysis; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D026901:Membrane Transport Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D011498:Protein Precursors; D029701:Saccharomyces cerevisiae Proteins; C083081:TIM23 protein, S cerevisiae; C469615:TIM50 protein, S cerevisiae; D010458:Peptidyl Transferases