Mitochondrial Targeting and Transport

Question	Answer
Length of Mitochondria target sequence	10-60 residues
Residues in Mitochondria target sequence	Alternate- +ve and hydrophobic
Structure of Mitochondrial Target Sequence	Forms an ampipathic helix- may or may no be cleavable
Import Pore- TOM40	4-8 monomers that form the pore
Import Pore- TOM22	Receptor for unfolded protein, and rebinds polypeptide when it's passed the pore to prevent it aggregating
Import Pore- TOM20/70	Associated receptors
Translationally Coupled- TOM20	Recognizes ampipathic helix of unfolded protein
Translationally Coupled- Chain of proteins	TOM20-TOM22-TOM5-TOM40
(Yeast) Post Translational- MSF	Mitochondrial Import Stimulating Factor
MSF binds...	Once protein has been folded by ribosomal (yeast) or cytoplasmic (mammals) chaperones
At pore, MSF interacts with	TOM70, which recognises it
Carrier proteins	Carry other molecules in and out of mitochondria, and also pass through pore
TIM23/27	Forms import pore
N-terminus of TIM23	Recognises MSF
TIM44	Recruits matrix Hsp70 (and Hsp40/NEF) to TIM complex to fold it as it enters the mitochondria
Lateral Gate	Allows protein to enter mitochondrial matrix
Mitochondrial Processing Peptide	Removes mitochondrial targeting factor (cleaves at penultimate residue)

Resource summary

	Created by gina_evans0312 about 12 years ago