VirB8-like protein TraH is crucial for DNA transfer in Enterococcus faecalis.
Untreatable bacterial infections caused by a perpetual increase of antibiotic resistant strains represent a serious threat to human healthcare in the 21(st) century. Conjugative DNA transfer is the most important mechanism for antibiotic resistance and virulence gene dissemination among bacteria and is mediated by a protein complex, known as type IV secretion system (T4SS). The core of the T4SS is a multiprotein complex that spans the bacterial envelope as a channel for macromolecular secretion. We report the NMR structure and functional characterization of the transfer protein TraH encoded by the conjugative Gram-positive broad-host range plasmid pIP501. The structure exhibits a striking similarity to VirB8 proteins of Gram-negative secretion systems where they play an essential role in the scaffold of the secretion machinery. Considering TraM as the first VirB8-like protein discovered in pIP501, TraH represents the second protein affiliated with this family in the respective transfer operon. A markerless traH deletion in pIP501 resulted in a total loss of transfer in Enterococcus faecalis as compared with the pIP501 wild type (wt) plasmid, demonstrating that TraH is essential for pIP501 mediated conjugation. Moreover, oligomerization state and topology of TraH in the native membrane were determined providing insights in molecular organization of a Gram-positive T4SS.
Institute of Molecular Biosciences, NAWI Graz, University of Graz, Austria.
Christian
C
Fercher
Division of Infectious Diseases, University Medical Center Freiburg, Germany.|Faculty of Biology, Microbiology, Albert-Ludwigs-University Freiburg, Germany.
Ines
I
Probst
Institute of Molecular Biosciences, NAWI Graz, University of Graz, Austria.
Verena
V
Kohler
Center for Structural System Biology (CSSB), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.|Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.|Institute of Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria.|Research Institute of Molecular Pathology (IMP), Vienna, Austria.
Nikolaus
N
Goessweiner-Mohr
Robert Koch Institute, Berlin, Germany.
Karsten
K
Arends
Division of Infectious Diseases, University Medical Center Freiburg, Germany.|Beuth University of Applied Sciences, Berlin, Germany.
Elisabeth
E
Grohmann
Institute of Chemistry, University of Graz, Graz, Austria.
Klaus
K
Zangger
Department of General and Visceral Surgery, University of Oldenburg, Germany.
N Helge
NH
Meyer
Institute of Molecular Biosciences, NAWI Graz, University of Graz, Austria.
Walter
W
Keller
D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D003227:Conjugation, Genetic; D004247:DNA / Q000378:metabolism*; D013293:Enterococcus faecalis / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D022761:Gene Transfer, Horizontal; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D011487:Protein Conformation
D001426:Bacterial Proteins; D009687:Nuclear Proteins; C065598:TraH protein, Bacteria; D004247:DNA