Chapter 10 Analysis and prediction of mitochondrial targeting peptides

This chapter reviews the characteristics of mitochondrial targeting peptides (mTPs) defined by statistical and experimental studies and discusses their use for predicting the presence of mTPs in protein sequences. Most methods for mTP prediction focus on the amino terminus of possible mitochondrial proteins. However, other portions of proteins also contribute to the import process. It is determined that C-terminal features of the small subunit of Rubisco modulate import of its precursor into chloroplasts. Some experimental evidences are provided for the existence of a cotranslational pathway for protein import into mitochondria. It has been demonstrated that the mTP is involved in the regulation of ribosome binding to the mitochondrial outer membrane. This import pathway may require additional, hitherto unknown mTP features. Thus, improved mTP prediction tools may have to account for features of the mature protein, rather than focusing only on the N-terminal parts of the precursor.