Charge cluster occurrence in land plants' mitochondrial proteomes with functional and structural insights

Area of Science:

• Mitochondrial Proteomics
• Bioinformatics
• Plant Biology

Background:

• Charge Clusters (CCs) are crucial for protein function and vary across organisms and protein types.
• Understanding CC distribution and roles in land plant mitochondria is essential for deciphering protein behavior.

Purpose of the Study:

• To conduct a large-scale investigation of CC occurrence, position, and function in land plant mitochondrial proteomes.
• To analyze CC conservation patterns within and between proteomes.

Main Methods:

• Utilized a novel Python script for data curation and the Finding Clusters Charge in Protein Sequences Program.
• Analyzed 44,316 protein sequences from 52 land plant species, adjusting the reading window size for CC detection.

Main Results:

• Negative Charge Clusters (NCCs) occur more frequently (1.2%) than Positive Charge Clusters (PCCs) (0.64%).
• Identified conserved NCCs and PCCs within and across proteomes, with mixed CCs being rare (0.12%).
• CCs are predominantly located in terminal regions, facilitating mitochondrial targeting and import, and are involved in binding functions crucial for processes like RNA editing and transcription.

Conclusions:

• CCs, despite low abundance, play a significant role in land plant mitochondrial protein targeting, import, and function.
• The findings provide valuable insights into CCs' contribution to plant adaptation and cellular processes.