Work

Crystal Structure of Escherichia coli CusC, the Outer Membrane Component of a Heavy Metal Efflux Pump

Year: 2011

Type: article

Abstract: BACKGROUND: While copper has essential functions as an enzymatic co-factor, excess copper ions are toxic for cells, necessitating mechanisms for regulating its levels. The cusCBFA operon of E. coli encodes a four-component efflux pump dedicated to the extrusion of Cu(I) and Ag(I) ions. METHODOLOGY/PRINCIPAL FINDINGS: We have solved the X-ray crystal structure of CusC, the outer membrane component of the Cus heavy metal efflux pump, to 2.3 Å resolution. The structure has the largest extracellular opening of any outer membrane factor (OMF) protein and suggests, for the first time, the presence of a tri-acylated N-terminal lipid anchor. CONCLUSIONS/SIGNIFICANCE: The CusC protein does not have any obvious features that would make it specific for metal ions, suggesting that the narrow substrate specificity of the pump is provided by other components of the pump, most likely by the inner membrane component CusA.

Source: PLoS ONE

DOI: 10.1371/journal.pone.0015610

Authors: Rithika Kulathila, Ragini Kulathila, Mridhu Indic, Bert van den Berg

Institution: University of Massachusetts Chan Medical School

Language: English

Topic: Bacterial Genetics and Biotechnology

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $2,382

Funders: National Institutes of Health, National Institute of General Medical Sciences