Family 2.A.54 - The Mitochondrial Tricarboxylate Carrier Family
Family ID: 53378
The MTC family consists of a limited number of homologues, all
from eukaryotes. A single member of the family has been functionally
characterized and sequenced. This is the tricarboxylate carrier
from rat liver mitochondria. It is 357 amino acyl residues in
length with 5 or 6 putative transmembrane a-helical spanners (TMSs).
It does not exhibit internal repeats or show homology to proteins
of the mitochondrial carrier family (TC #2.A.29). Homologues are
found in Caenorhabditis elegans, Saccharomyces cerevisiae and
Leishmania major. They are of 285-293 amino acyl residues with
one exception, and are reported to possess 3-6 putative TMSs.
The rat liver
mitochondrial tricarboxylate carrier has been reported to transport
citrate, cis-aconitate, threo-D-isocitrate, D- and L-tartrate,
malate, succinate and phosphoenolpyruvate. Trans-aconitate, a-ketoglutarate
and malonate are not substrates. It presumably functions by a
proton symport mechanism for the uptake of the variety of anionic
substrates listed above.
