title: Structural basis of enzyme encapsulation into a bacterial nanocompartment.
abstract: Compartmentalization is an important organizational feature of life. It occurs at varying levels of complexity ranging from eukaryotic organelles and the bacterial microcompartments, to the molecular reaction chambers formed by enzyme assemblies. The structural basis of enzyme encapsulation in molecular compartments is poorly understood. Here we show, using X-ray crystallographic, biochemical and EM experiments, that a widespread family of conserved bacterial proteins, the linocin-like proteins, form large assemblies that function as a minimal compartment to package enzymes. We refer to this shell-forming protein as 'encapsulin'. The crystal structure of such a particle from Thermotoga maritima determined at 3.1-angstroms resolution reveals that 60 copies of the monomer assemble into a thin, icosahedral shell with a diameter of 240 angstroms. The interior of this nanocompartment is lined with conserved binding sites for short polypeptide tags present as C-terminal extensions of enzymes involved in oxidative-stress response.
authors.affiliation: ETH Zurich, Institute of Molecular Biology and Biophysics, Schafmattstrasse 20, 8093 Zurich, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Sutter
authors.forename: Daniel
authors.initials: D
authors.lastname: Boehringer
authors.forename: Sascha
authors.initials: S
authors.lastname: Gutmann
authors.forename: Susanne
authors.initials: S
authors.lastname: Günther
authors.forename: David
authors.initials: D
authors.lastname: Prangishvili
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Loessner
authors.forename: Karl O
authors.initials: KO
authors.lastname: Stetter
authors.forename: Eilika
authors.initials: E
authors.lastname: Weber-Ban
authors.forename: Nenad
authors.initials: N
authors.lastname: Ban
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001665:Binding Sites; D001951:Brevibacterium / Q000201:enzymology / Q000235:genetics / Q000648:ultrastructure; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes / Q000737:chemistry; D015388:Organelles / Q000201:enzymology / Q000648:ultrastructure; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D020124:Thermotoga maritima / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure*
chemical_list: D001426:Bacterial Proteins; D046912:Multiprotein Complexes; D011994:Recombinant Proteins