Structure and mechanisms of a protein-based organelle in Escherichia coli.
Many bacterial cells contain proteinaceous microcompartments that act as simple organelles by sequestering specific metabolic processes involving volatile or toxic metabolites. Here we report the three-dimensional (3D) crystal structures, with resolutions between 1.65 and 2.5 angstroms, of the four homologous proteins (EutS, EutL, EutK, and EutM) that are thought to be the major shell constituents of a functionally complex ethanolamine utilization (Eut) microcompartment. The Eut microcompartment is used to sequester the metabolism of ethanolamine in bacteria such as Escherichia coli and Salmonella enterica. The four Eut shell proteins share an overall similar 3D fold, but they have distinguishing structural features that help explain the specific roles they play in the microcompartment. For example, EutL undergoes a conformational change that is probably involved in gating molecular transport through shell protein pores, whereas structural evidence suggests that EutK might bind a nucleic acid component. Together these structures give mechanistic insight into bacterial microcompartments.
Tanaka
Shiho
S
Department of Chemistry and Biochemistry, University of California Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA.
Sawaya
Michael R
MR
Yeates
Todd O
TO
D000595:Amino Acid Sequence; D002451:Cell Compartmentation; D018360:Crystallography, X-Ray; D048168:Escherichia coli K12 / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D019856:Ethanolamine / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020815:Polyproteins / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism
D029968:Escherichia coli Proteins; C546569:EutK protein, E coli; C541333:EutL protein, E coli; C546563:EutM protein, E coli; C546562:EutS protein, E coli; D020815:Polyproteins; D021122:Protein Subunits; D019856:Ethanolamine