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Updated: May 8, 2026
14:06
Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
Published on: November 12, 2012
Sigma factors in a thousand E. coli genomes.
1Department of Systems Biology, Center for Biological Sequence Analysis, The Technical University of Denmark, 2800 Kgs, Lyngby, Denmark.
Environmental Microbiology
|September 3, 2013
Summary
Analyzing bacterial genomics data is challenging. This study introduces genome quality scoring and protein family searching methods to manage the vast amount of genomic information, particularly for Escherichia coli.
Area of Science:
- Genomics
- Bioinformatics
- Microbiology
Background:
- Bacterial genomics generates vast datasets, posing challenges for analysis.
- Existing methods for managing and analyzing large genomic datasets are insufficient.
- Comparative genomic studies require high-quality, well-assembled genome data.
Purpose of the Study:
- To introduce and evaluate methods for managing and analyzing large bacterial genomic datasets.
- To assess the quality of available Escherichia coli genomes for comparative genomics.
- To identify conserved and novel protein families, including sigma factors, within E. coli genomes.
Main Methods:
- Development of a genome quality scoring system.
- Implementation of a method for rapid sorting of genomes based on protein families.
- Application of these methods to all available E. coli genomes in the NCBI database.
Main Results:
- Less than half of the analyzed E. coli/Shigella genomes (983 out of 2074) met quality standards for comparative genomics.
- Significant variation in genome assembly quality was observed, with some 'draft' genomes being of higher quality than 'complete' ones.
- Six of seven sigma factors in E. coli strain K-12 are conserved; FecI (σ(19)) is frequently absent. A potential novel sigma factor was identified in over a hundred E. coli genomes.
- The E. coli strain CFT073 genome appears to lack a functional RpoD (σ(70)), likely due to assembly/annotation errors.
Conclusions:
- Genome quality scoring and targeted protein family searching are essential tools for managing large-scale bacterial genomics data.
- A substantial portion of publicly available E. coli genomes are not suitable for high-confidence comparative genomic analyses.
- The study highlights the importance of accurate genome assembly and annotation, and reveals insights into sigma factor conservation and potential novelty in E. coli.
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