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Updated: Aug 9, 2026

Assessment of Submitochondrial Protein Localization in Budding Yeast Saccharomyces cerevisiae
Published on: July 19, 2021
Crystal structure of yeast mitochondrial peripheral membrane protein Tim44p C-terminal domain
Ratnakar Josyula1, Zhongmin Jin, Zhengqing Fu
1Department of Cell Biology, Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, AL 35294-0005, USA.
Abstract:
The protein transports from the cell cytosol to the mitochondria matrix are carried out by the translocase of the outer membrane (TOM) complex and the translocase of the inner membrane (TIM) complexes. Tim44p is an essential mitochondrial peripheral membrane protein and a major component of TIM23 translocon. Tim44p can tightly associate with the inner mitochondrial membrane. To investigate the mechanism by which Tim44p functions in the TIM23 translocon to deliver the mitochondrial protein precursors, we have determined the crystal structure of the yeast Tim44p C-terminal domain to 3.2A resolution using the MAD method. The Tim44p C-terminal domain forms a monomer in the crystal structure and contains six alpha-helices and four antiparallel beta-strands. A large hydrophobic pocket was identified on the Tim44p structure surface. The N-terminal helix A1 is positively charged and the helix A1 protrudes out from the Tim44p main body.
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