Mitochondrial carriers
Mitochondrial carriers form a family of transport proteins that belong to the carriers (permeases) and occur only in the organelle (mostly in mitochondria ) membranes of eukaryotic cells . They consist of about 300 amino acids and have six α-helices in the secondary structure . From an evolutionary point of view , the basic structure was probably formed about two billion years ago through intragenetic gene triple multiplication of a precursor with two α-helices .
The majority of these mitochondrial carriers , which are related to one another in evolutionary biology, catalyze the antiport of two substances such as keto acids , amino acids , nucleotides , inorganic ions and cofactors .
The transport equation for the antiport is:
- Fabric1 inside + Fabric2 outside Fabric1 outside + Fabric2 inside .
Outside of mitochondria, mitochondrial carriers were found in peroxisomes of various animals, in hydrogenosomes of anaerobic fungi and in plant amyloplasts . About 50 of them are known in humans; they are mainly from the SLC25 - genes coding . Mutations in eleven of these genes can be responsible for defects in one of the proteins and the cause of (rare) hereditary diseases, such as: Defects in the ATP / ADP translocase , in the carnitine-acylcarnitine transporter , in the phosphate transporter and in the Aspartate-glutamate carrier .