Identification of MIM23, a putative component of the protein import machinery of the mitochondrial inner membrane.
A screening for yeast mutants impaired in mitochondrial protein import led to the identification of two genes (MPII and MPI2) encoding the essential components MIM44 and MIM17 of the inner membrane import machinery. We analyzed twelve additional mutants obtained in the screening and found two further complementation groups. One group represents mutants of SSC1, the gene encoding mitochondrial hsp70, an essential matrix protein required for protein import across the inner membrane. The second complementation group represents mutants of a new gene (MP13) encoding a 23 kDa integral inner membrane protein (MIM23). MIM23 is synthesized without a presequence, and its import to the inner membrane requires a membrane potential. MIM23 contains a domain homologous to half of MIM17. We speculate that MIM23 is a new member of the protein import machinery of the mitochondrial inner membrane.
Dekker
P J
PJ
Institute for Molecular Cell Biology, BioCentrum Amsterdam, The Netherlands.
Keil
P
P
Rassow
J
J
Maarse
A C
AC
Pfanner
N
N
Meijer
M
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D004271:DNA, Fungal; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008928:Mitochondria / Q000378:metabolism*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid
D002352:Carrier Proteins; D004271:DNA, Fungal; D005656:Fungal Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D029701:Saccharomyces cerevisiae Proteins; C083081:TIM23 protein, S cerevisiae