Discovery and characterization of a novel family of prokaryotic nanocompartments involved in sulfur metabolism

eLife

Amanda J Bischoff¹  Devon R Radford²  Luke M Oltrogge³  David F Savage³  Robert J Nichols³  Naiya R Phillips³  Benjamin LaFrance³  Eva Nogales⁴  Luis E Valentin-Alvarado⁵ 

[1] Department of Chemistry, University of California Berkeley, Berkeley, United States;Department of Molecular Genetics, University of Toronto, Toronto, Canada;Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States;Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States;Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States;Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, United States;California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, United States;Molecular Biophysics and Integrated Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, United States;Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, United States;

关键词: Synechococcus elongatus;    nanocompartment;    encapsulin;    prokaryotic organelle;    sulfur starvation;    cryo-EM;    E. coli;    Other;   

DOI  :  10.7554/eLife.59288

来源: eLife Sciences Publications, Ltd

【 摘 要 】

Prokaryotic nanocompartments, also known as encapsulins, are a recently discovered proteinaceous organelle-like compartment in prokaryotes that compartmentalize cargo enzymes. While initial studies have begun to elucidate the structure and physiological roles of encapsulins, bioinformatic evidence suggests that a great diversity of encapsulin nanocompartments remains unexplored. Here, we describe a novel encapsulin in the freshwater cyanobacterium Synechococcus elongatus PCC 7942. This nanocompartment is upregulated upon sulfate starvation and encapsulates a cysteine desulfurase enzyme via an N-terminal targeting sequence. Using cryo-electron microscopy, we have determined the structure of the nanocompartment complex to 2.2 Å resolution. Lastly, biochemical characterization of the complex demonstrated that the activity of the cysteine desulfurase is enhanced upon encapsulation. Taken together, our discovery, structural analysis, and enzymatic characterization of this prokaryotic nanocompartment provide a foundation for future studies seeking to understand the physiological role of this encapsulin in various bacteria.

【 授权许可】

CC BY