Question

Which of the following protein(s) complexes is directly required for the targeting of mitochondrial inner membrane proteins?

1) OXA
2) Mia40
3) TIM
4) SAM

Answer 1

TIM and OXA protein complexes are required for targeting proteins to the inner membrane of mitochondria, whereas Mia40 and SAM are not directly involved.

Step-by-step explanation:

The protein complexes directly required for the targeting of mitochondrial inner membrane proteins include the Translocase of Inner Mitochondrial Membrane (TIM) and the Oxidase Assembly (OXA) complexes. The TIM complex facilitates the translocation of proteins across or into the inner membrane, while the OXA complex is involved in inserting mitochondrially encoded proteins, as well as some imported proteins, into the inner membrane. It is important to note that the Mia40 and SAM complexes are related to intermembrane space and outer membrane proteins, respectively, hence they do not play a direct role in the targeting of proteins to the inner membrane.