Cross-Species Functional Conservation and Possible Origin of the N-Terminal Specificity Domain of Mitochondrial Presequences

Dong Wook Lee; Sumin Lee; Chan-Ki Min; Cana Park; Jeong-Mok Kim; Cheol-Sang Hwang; Sang Ki Park; Nam-Hyuk Cho; Inhwan Hwang

doi:10.3389/fpls.2020.00064

Cross-Species Functional Conservation and Possible Origin of the N-Terminal Specificity Domain of Mitochondrial Presequences

Front Plant Sci. 2020 Feb 13:11:64. doi: 10.3389/fpls.2020.00064. eCollection 2020.

Authors

Dong Wook Lee^{1

2

3}, Sumin Lee⁴, Chan-Ki Min⁵, Cana Park⁴, Jeong-Mok Kim⁴, Cheol-Sang Hwang⁴, Sang Ki Park⁴, Nam-Hyuk Cho⁵, Inhwan Hwang^{1

4}

Affiliations

¹ Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea.
² Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea.
³ Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, South Korea.
⁴ Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea.
⁵ Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, South Korea.

Abstract

Plants have two endosymbiotic organelles, chloroplast and mitochondrion. Although they have their own genomes, proteome assembly in these organelles depends on the import of proteins encoded by the nuclear genome. Previously, we elucidated the general design principles of chloroplast and mitochondrial targeting signals, transit peptide, and presequence, respectively, which are highly diverse in primary structure. Both targeting signals are composed of N-terminal specificity domain and C-terminal translocation domain. Especially, the N-terminal specificity domain of mitochondrial presequences contains multiple arginine residues and hydrophobic sequence motif. In this study we investigated whether the design principles of plant mitochondrial presequences can be applied to those in other eukaryotic species. We provide evidence that both presequences and import mechanisms are remarkably conserved throughout the species. In addition, we present evidence that the N-terminal specificity domain of presequence might have evolved from the bacterial TAT (twin-arginine translocation) signal sequence.

Keywords: N-terminal specificity domain; TAT (twin-arginine translocation) signal sequence; chloroplast; evolution of endosymbiotic organelles; mitochondria; presequence; transit peptide.