Structural biology of MCR-1-mediated resistance to polymyxin antibiotics

Area of Science:

• Microbiology
• Biochemistry
• Drug Discovery

Background:

• Polymyxins are critical last-resort antibiotics against multidrug-resistant Gram-negative bacteria.
• The plasmid-encoded enzyme MCR-1 confers resistance by modifying the bacterial outer membrane.
• Transferable polymyxin resistance via MCR-1 is a significant global health concern, necessitating MCR-1 as a key drug target.

Purpose of the Study:

• To review recent structural and mechanistic insights into MCR-1 function.
• To explore MCR-1 variants and homologs in the context of polymyxin resistance.
• To discuss advancements in the development of MCR-1 inhibitors.

Main Methods:

• Analysis of polymyxin-mediated disruption of bacterial membranes.
• Computational studies elucidating the catalytic mechanism of MCR-1.
• Mutagenesis and structural analyses to identify key residues for substrate binding.
• Review of emerging strategies for MCR-1 inhibitor development.

Main Results:

• Detailed understanding of how MCR-1 modifies the outer membrane to confer resistance.
• Identification of critical amino acid residues involved in MCR-1 substrate binding and catalysis.
• Insights into the structural basis of polymyxin resistance mediated by MCR-1 and its variants.
• Progress in designing novel inhibitors targeting the MCR-1 enzyme.

Conclusions:

• MCR-1 is a critical determinant of transferable polymyxin resistance.
• Structural and mechanistic studies provide a foundation for rational drug design against MCR-1.
• Targeting MCR-1 offers a promising strategy to restore polymyxin efficacy against resistant pathogens.