TY - JOUR
T1 - The protein import channel in the outer mitosomal membrane of Giardia intestinalis
AU - Dagley, Michael J
AU - Dolezal, Pavel
AU - Likic, Vladimir A
AU - Smid, Ondrej
AU - Purcell, Anthony Wayne
AU - Buchanan, Susan K
AU - Tachezy, Jan
AU - Lithgow, Trevor James
PY - 2009
Y1 - 2009
N2 - The identification of mitosomes in Giardia generated significant debate on the evolutionary origin of these organelles; whether they were highly reduced mitochondria, or the product of a unique endosymbiotic event in an amitochondrial organism. As the protein import pathway is a defining characteristic of mitochondria, we sought to discover a TOM (translocase in the outer mitochondrial membrane) complex in Giardia. A Hidden Markov model search of the Giardia genome identified a Tom40 homologous sequence (GiTom40), where Tom40 is the protein translocation channel of the TOM complex. The GiTom40 protein is located in the membrane of mitosomes in a approximately 200 kDa TOM complex. As Tom40 was derived in the development of mitochondria to serve as the protein import channel in the outer membrane, its presence in Giardia evidences the mitochondrial ancestry of mitosomes.
AB - The identification of mitosomes in Giardia generated significant debate on the evolutionary origin of these organelles; whether they were highly reduced mitochondria, or the product of a unique endosymbiotic event in an amitochondrial organism. As the protein import pathway is a defining characteristic of mitochondria, we sought to discover a TOM (translocase in the outer mitochondrial membrane) complex in Giardia. A Hidden Markov model search of the Giardia genome identified a Tom40 homologous sequence (GiTom40), where Tom40 is the protein translocation channel of the TOM complex. The GiTom40 protein is located in the membrane of mitosomes in a approximately 200 kDa TOM complex. As Tom40 was derived in the development of mitochondria to serve as the protein import channel in the outer membrane, its presence in Giardia evidences the mitochondrial ancestry of mitosomes.
UR - http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19531743
U2 - 10.1093/molbev/msp117
DO - 10.1093/molbev/msp117
M3 - Article
SN - 0737-4038
VL - 26
SP - 1941
EP - 1947
JO - Molecular Biology and Evolution
JF - Molecular Biology and Evolution
IS - 9
ER -