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Published on: October 15, 2019
Comparative analysis of hmuO function and expression in Corynebacterium species
Carey A Kunkle1, Michael P Schmitt
1Laboratory of Respiratory and Special Pathogens, Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, Food and Drug Adminisstration, Bethesda, MD 20892, USA.
Journal of Bacteriology
|February 27, 2007
Summary
Variations in the hmuO gene between Corynebacterium diphtheriae and Corynebacterium ulcerans impact heme-iron utilization. C. ulcerans hmuO mutations significantly reduce heme use, unlike in C. diphtheriae.
Area of Science:
- Microbiology
- Molecular Biology
- Bacterial Pathogenesis
Background:
- Heme is a crucial iron source for many bacteria, including Corynebacterium species.
- The hmuO gene is implicated in heme utilization in various bacterial pathogens.
- Understanding heme uptake mechanisms is vital for controlling infections caused by Corynebacterium.
Purpose of the Study:
- To investigate the role of the hmuO gene in heme-iron utilization in Corynebacterium diphtheriae and Corynebacterium ulcerans.
- To compare the regulation of hmuO gene expression in response to iron and heme availability between these two species.
Main Methods:
- Construction of defined deletions in the hmuO gene of C. diphtheriae and C. ulcerans.
- Assessment of hemoglobin-iron and heme utilization in wild-type and mutant strains.
- Analysis of hmuO promoter activity and its regulation by iron and heme.
Main Results:
- Deletion of hmuO in C. ulcerans significantly impaired heme-iron utilization.
- hmuO deletion in C. diphtheriae resulted in only a partial reduction in heme utilization.
- The C. ulcerans hmuO promoter showed minimal iron or heme regulation, while the C. diphtheriae promoter exhibited strong iron repression and heme-dependent activation.
Conclusions:
- Functional and regulatory differences in the hmuO gene exist between C. diphtheriae and C. ulcerans.
- These variations contribute to distinct heme-iron acquisition strategies in these related bacterial species.
- The findings highlight the importance of species-specific analysis of iron acquisition systems in Corynebacterium.
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