Final answer:
The TIM22 complex is the key component required for targeting mitochondrial inner membrane multipass proteins that do not have cleavable signal sequences, such as metabolite transporters.
Step-by-step explanation:
The protein directly required for the targeting of mitochondrial inner membrane multipass proteins, such as metabolite transporters whose signal sequence is normally not cleaved after import, is the TIM22 complex
This translocator is responsible for inserting hydrophobic membrane proteins into the mitochondrial inner membrane. While TIM23 is involved in importing matrix-targeted proteins and inner membrane proteins with a cleavable presequence, the TIM22 complex specializes in the insertion of multi-pass transmembrane proteins, such as metabolite transporters that do not have a cleavable presequence. As such, mitochondrial protein import is an intricate process that differs based on the destination and characteristics of the proteins being transported. The heat-shock proteins (HSP70), on the other hand, are involved in unfolding proteins as they pass into the matrix and then aiding in their refolding.