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Updated: Aug 7, 2026
12:11
Methodology for Accurate Detection of Mitochondrial DNA Methylation
Published on: May 20, 2018
Heat shock protein 60 sequence comparisons: duplications, lateral transfer, and mitochondrial evolution
1Department of Mathematics, Stanford University, Stanford, CA 94305-2125, USA. karlin@math.stanford.edu
Summary
Heat shock proteins 60 (HSP60) are crucial for bacterial and organelle function. Their sequences help trace mitochondrial genome evolution, suggesting a bacterial origin via lateral gene transfer from alpha-proteobacteria.
Area of Science:
- Evolutionary biology
- Genomics
- Molecular biology
Background:
- Heat shock proteins 60 (HSP60), also known as GroEL, are essential proteins found in eubacterial and eukaryotic organelles.
- These chaperone proteins are proposed as valuable markers for studying mitochondrial (Mt) genome evolution.
Purpose of the Study:
- To investigate the evolutionary relationships of mitochondrial genomes using HSP60 sequences.
- To explore the role of HSP60 duplications in alpha-proteobacteria and their connection to lateral gene transfer and plasmid integration.
Main Methods:
- Sequence similarity analysis using segment pair alignment calculations.
- Multiple sequence alignments and consensus determination for 10 natural groups.
- Comparison of mitochondrial HSP60 sequences with various proteobacterial groups.
Main Results:
- Mitochondrial HSP60 sequences show the strongest similarity to classical alpha-proteobacteria and Rickettsia.
- No single prokaryote consistently aligns best with animal mitochondrial genomes across broad comparisons.
- Duplicated HSP60 sequences are prevalent in classical alpha-proteobacteria but absent in other proteobacterial clades.
Conclusions:
- Nuclear-encoded HSP60 sequences in mitochondria likely originated from alpha-proteobacteria through lateral gene transfer.
- The pattern of HSP60 duplications supports the hypothesis of lateral transfer and integration events in early evolutionary history.
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