Resistance-nodulation-cell division superfamily

Crystallized AcrB HAE-RND efflux protein

Resistance-nodulation-cell division superfamily

The Resistance-nodulation-cell division (RND) superfamily is a group of proteins that play a crucial role in the transport of various molecules across cell membranes in bacteria, archaea, and eukaryotes. Members of the RND superfamily are involved in multidrug resistance, heavy metal resistance, and efflux of toxic compounds from cells.

Structure and Function

The RND superfamily proteins typically consist of three domains: the periplasmic adaptor protein (PAP), the inner membrane transporter (IMT), and the outer membrane factor (OMF). These proteins work together to form a complex that spans the entire cell envelope and facilitates the efflux of substrates out of the cell.

The primary function of RND superfamily proteins is to pump a wide range of substrates, including antibiotics, detergents, and heavy metals, out of the cell. This efflux mechanism helps the cell survive in hostile environments by preventing the accumulation of toxic compounds inside the cell.

Role in Antibiotic Resistance

One of the most well-known functions of the RND superfamily is its role in antibiotic resistance. Bacterial pathogens can develop resistance to multiple antibiotics by overexpressing RND superfamily efflux pumps, which actively pump antibiotics out of the cell, reducing their effectiveness.

Evolutionary Conservation

The RND superfamily is evolutionarily conserved across diverse organisms, highlighting its importance in cellular physiology and survival. The structural and functional similarities of RND proteins in different organisms suggest a common evolutionary origin and a fundamental role in cellular homeostasis.

Clinical Implications

Understanding the mechanisms of RND superfamily proteins is crucial for developing strategies to combat antibiotic resistance in pathogenic bacteria. Targeting these efflux pumps with specific inhibitors could enhance the efficacy of existing antibiotics and help overcome multidrug resistance in bacterial infections.

See Also

• Efflux pump
• Antibiotic resistance
• Cell membrane transport

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