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Evolution and Sequence Diversity of FhuA in Salmonella and Escherichia
- Source :
- Infection and Immunity. 86
- Publication Year :
- 2018
- Publisher :
- American Society for Microbiology, 2018.
-
Abstract
- The fhuACDB operon, present in a number of Enterobacteriaceae, encodes components essential for the uptake of ferric hydroxamate type siderophores. FhuA acts not only as a transporter for physiologically important chelated ferric iron but also as a receptor for various bacteriophages, toxins, and antibiotics, which are pathogenic to bacterial cells. In this research, fhuA gene distribution and sequence diversity were investigated in Enterobacteriaceae, especially Salmonella and Escherichia. Comparative sequence analysis resulted in a fhuA phylogenetic tree that did not match the expected phylogeny of species or trees of the fhuCDB genes. The fhuA sequences showed a unique mosaic clustering pattern. On the other hand, the gene sequences showed high conservation for strains from the same serovar or serotype. In total, six clusters were identified from FhuA proteins in Salmonella and Escherichia, among which typical peptide fragment variations could be defined. Six fragmental insertions/deletions and two substitution fragments were discovered, for which the combination of polymorphism patterns could well classify the different clusters. Structural modeling demonstrated that all the six featured insertions/deletions and one substitution fragment are located at the apexes of the long loops present as part of the FhuA external pocket. These frequently mutated regions are likely under high selection pressure, with bacterial strains balancing escape from phage infection or toxin/antibiotics attack via fhuA gene mutations while maintaining the siderophore uptake activity essential for bacterial survival. The unusual fhuA clustering suggests that high-frequency exchange of fhuA genes has occurred between enterobacterial strains after distinctive species were established.
- Subjects :
- Escherichia
Models, Molecular
0301 basic medicine
Salmonella
Operon
Sequence analysis
Immunology
Sequence Homology
Molecular Genomics
Gene mutation
medicine.disease_cause
Microbiology
Evolution, Molecular
03 medical and health sciences
Phylogenetics
medicine
Cluster Analysis
Gene
Phylogeny
Genetics
biology
Escherichia coli Proteins
Genetic Variation
Membrane Transport Proteins
Sequence Analysis, DNA
biology.organism_classification
Enterobacteriaceae
030104 developmental biology
Infectious Diseases
Receptors, Virus
Parasitology
Bacterial Outer Membrane Proteins
Subjects
Details
- ISSN :
- 10985522 and 00199567
- Volume :
- 86
- Database :
- OpenAIRE
- Journal :
- Infection and Immunity
- Accession number :
- edsair.doi.dedup.....3a6127da1605b0509fb5c258383db63c