Why is manganese so valuable to bacterial pathogens?

Area of Science:

• Microbiology
• Biochemistry
• Evolutionary Biology

Background:

• Manganese utilization in bacteria varies, unlike essential iron.
• Oxygen accumulation in Earth's atmosphere linked manganese and iron use.
• Oxygen enhances oxidative stress, prompting bacterial iron control mechanisms.

Purpose of the Study:

• Explain manganese's role in bacterial pathogens.
• Detail how molecular oxygen affects iron and manganese utilization.
• Explore manganese's ability to replace iron in enzymes.

Main Methods:

• Review of existing literature on manganese and iron metabolism in bacteria.
• Analysis of how molecular oxygen influences metal-dependent enzymes.
• Examination of evolutionary pressures driving metal selection in pathogens.

Main Results:

• Molecular oxygen's interaction with iron increases oxidative stress.
• Bacteria evolved mechanisms to control intracellular free iron.
• Manganese can substitute for iron in certain enzymes, especially redox-inactive ones.
• Specific manganese-dependent isoenzymes evolved to manage manganese's higher redox potential in redox-active enzymes.

Conclusions:

• The evolution of oxygen shaped bacterial metal utilization strategies.
• Manganese is highly valued by pathogens due to its ability to substitute for iron.
• Host-pathogen interactions involve a complex competition for manganese.
• Cytosolic conditions are critical for determining metal selection in enzymes.