Indicate true (T) and false (F) statements below regarding the mitochondrial protein import system. Your answer would be a four-letter string composed of letters T and F only, e.g. TTTF.
( ) Mitochondrial proteins should fold natively twice: once in the cytosol and once inside the organelle.
( ) ?-barrel proteins that are abundant in the mitochondrial outer membrane are imported from the cytosol independently of the TOM complex.
( ) Signal sequences that target precursor proteins to the mitochondrial matrix form an ?- helix in which positively charged residues cluster near its N-terminus, while uncharged or hydrophobic residues cluster near the other side.
( ) At least two signal sequences are required to direct proteins to the mitochondrial matrix.