Document Type
Article
Department/Program
Biology
Pub Date
1-2000
Abstract
The mitochondrial inner membrane contains two separate translocons: one required for the translocation of matrix-targeted proteins (the Tim23p-Tim17p complex) and one for the insertion of polytopic proteins into the mitochondrial inner membrane (the Tim54p-Tim22p complex). To identify new members of the Tim54p-Tim22p complex, we screened for high-copy suppressors of the temperature-sensitivetim54-1 mutant. We identified a new gene,TIM18, that encodes an integral protein of the inner membrane. The following genetic and biochemical observations suggest that the Tim18 protein is part of the Tim54p-Tim22p complex in the inner membrane: multiple copies of TIM18 suppress thetim54-1 growth defect; thetim18::HIS3 disruption is synthetically lethal with tim54-1; Tim54p and Tim22p can be coimmune precipitated with the Tim18 protein; and Tim18p, along with Tim54p and Tim22p, is detected in an ∼300-kDa complex after blue native electrophoresis. We propose that Tim18p is a new component of the Tim54p-Tim22p machinery that facilitates insertion of polytopic proteins into the mitochondrial inner membrane.
Recommended Citation
Kerscher, Oliver; Sepuri, Naresh B.; and Jensen, Robert E., Tim18p Is a New Component of the Tim54p-Tim22p Translocon in the Mitochondrial Inner Membrane (2000).
https://doi.org/10.1091/mbc.11.1.103
DOI
https://doi.org/10.1091/mbc.11.1.103
Publisher Statement
This work was supported by grant R01-GM46803 from the U.S. Public Health Service to R.E.J.
