Publication - Journal Article Shewanella oneidensis MR-1 nanowires are outer membrane and periplasmic extensions of the extracellular electron transport components

Proceedings of the National Academy of Sciences, vol. 111, iss. 35, pp. 12883-12888, 2014

Sahand Pirbadian, Sarah E. Barchinger, Kar Man Leung, Hye Suk Byun, Yamini Jangir, Rachida A. Bouhenni, Samantha B. Reed, Margaret F. Romine, Daad A. Saffarini, Liang Shi, Yuri A. Gorby, John H. Golbeck, Mohamed Y. El-Naggar

Significance Bacterial nanowires from Shewanella oneidensis MR-1 were previously shown to be conductive under nonphysiological conditions. Intense debate still surrounds the molecular makeup, identity of the charge carriers, and cellular respiratory impact of bacterial nanowires. In this work, using in vivo fluorescence measurements, immunolabeling, and quantitative gene expression analysis, we demonstrate that S. oneidensis MR-1 nanowires are extensions of the outer membrane and periplasm, rather than pilin-based structures, as previously thought. We also demonstrate that the outer membrane multiheme cytochromes MtrC and OmcA localize to these membrane extensions, directly supporting one of the two models of electron transport through the nanowires; consistent with this, production of bacterial nanowires correlates with an increase in cellular reductase activity.