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The life-cycle of operons
Morgan N Price1, Adam P Arkin, Eric J Alm
1Lawrence Berkeley National Laboratory, Berkeley, California, USA.
Plos Genetics
|June 23, 2006
Summary
Operon evolution in prokaryotes is driven by changes in gene expression. Gene order shifts, operon formation, and destruction impact gene regulation and genome structure.
Area of Science:
- Genomics
- Molecular Biology
- Evolutionary Biology
Background:
- Operons are fundamental to prokaryotic genomes.
- The mechanisms and drivers of operon structure variation remain poorly understood.
Purpose of the Study:
- To investigate the life-cycle of operons.
- To understand how operon structures form, change, and are eliminated in prokaryotes.
Main Methods:
- Comparative genomics of gene order in Escherichia coli and related species.
- Identification of newly formed and recently destroyed operons.
- Analysis of gene expression patterns in relation to operon evolution.
Main Results:
- Operon creation and destruction significantly alter gene expression patterns.
- Examples include adaptation to lysine levels and DNA damage responses.
- Some operons exhibit accelerated evolution with rapid gene acquisition.
- Highly expressed operons show wider gene spacing due to regulatory fine-tuning.
Conclusions:
- Operon evolution is likely driven by selection on gene expression patterns.
- While adaptive, operon evolution is not always optimal, with unrelated genes sometimes co-opting into new operons.
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