Nuclear Pore-Like Structures in a Compartmentalized Bacterium.
Planctomycetes are distinguished from other Bacteria by compartmentalization of cells via internal membranes, interpretation of which has been subject to recent debate regarding potential relations to Gram-negative cell structure. In our interpretation of the available data, the planctomycete Gemmata obscuriglobus contains a nuclear body compartment, and thus possesses a type of cell organization with parallels to the eukaryote nucleus. Here we show that pore-like structures occur in internal membranes of G.obscuriglobus and that they have elements structurally similar to eukaryote nuclear pores, including a basket, ring-spoke structure, and eight-fold rotational symmetry. Bioinformatic analysis of proteomic data reveals that some of the G. obscuriglobus proteins associated with pore-containing membranes possess structural domains found in eukaryote nuclear pore complexes. Moreover, immunogold labelling demonstrates localization of one such protein, containing a β-propeller domain, specifically to the G. obscuriglobus pore-like structures. Finding bacterial pores within internal cell membranes and with structural similarities to eukaryote nuclear pore complexes raises the dual possibilities of either hitherto undetected homology or stunning evolutionary convergence.
School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
Evgeny
E
Sagulenko
School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
Amanda
A
Nouwens
Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Queensland, Australia.
Richard I
RI
Webb
Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Queensland, Australia.
Kathryn
K
Green
School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
Benjamin
B
Yee
Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Queensland, Australia.
Garry
G
Morgan
CSIRO - Livestock Industries, Australian Animal Health Laboratory, Biosecurity Microscopy Facility (ABMF), Geelong, Victoria, Australia.
Andrew
A
Leis
School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
Kuo-Chang
KC
Lee
School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
Margaret K
MK
Butler
Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
Nicholas
N
Chia
School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
Uyen Thi Phuong
UT
Pham
School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
Stinus
S
Lindgreen
School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.|Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.
Ryan
R
Catchpole
School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.|Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.|Allan Wilson Centre, University of Canterbury, Christchurch, New Zealand.|Bioinformatics Institute, School of Biological Sciences, University of Auckland, Auckland, New Zealand.
Anthony M
AM
Poole
School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
John A
JA
Fuerst
D001419:Bacteria / Q000378:metabolism / Q000648:ultrastructure*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D005075:Biological Evolution; D002451:Cell Compartmentation; D002473:Cell Wall / Q000378:metabolism; D019295:Computational Biology / Q000379:methods; D056890:Eukaryota / Q000648:ultrastructure; D021621:Imaging, Three-Dimensional; D007425:Intracellular Membranes / Q000648:ultrastructure; D008958:Models, Molecular; D022022:Nuclear Pore / Q000648:ultrastructure*; D061328:Planctomycetales / Q000648:ultrastructure; D011487:Protein Conformation; D020543:Proteome; D040901:Proteomics
D001426:Bacterial Proteins; D020543:Proteome