Journal article

Crystal structure of TcpK in complex with oriT DNA of the antibiotic resistance plasmid pCW3

Daouda AK Traore, Jessica A Wisniewski, Sarena F Flanigan, Paul J Conroy, Santosh Panjikar, Yee-Foong Mok, Carmen Lao, Michael DW Griffin, Vicki Adams, Julian I Rood, James C Whisstock

Nature Communications | NATURE PUBLISHING GROUP | Published : 2018


Conjugation is fundamental for the acquisition of new genetic traits and the development of antibiotic resistance in pathogenic organisms. Here, we show that a hypothetical Clostridium perfringens protein, TcpK, which is encoded by the tetracycline resistance plasmid pCW3, is essential for efficient conjugative DNA transfer. Our studies reveal that TcpK is a member of the winged helix-turn-helix (wHTH) transcription factor superfamily and that it forms a dimer in solution. Furthermore, TcpK specifically binds to a nine-nucleotide sequence that is present as tandem repeats within the pCW3 origin of transfer (oriT). The X-ray crystal structure of the TcpK-TcpK box complex reveals a binding mod..

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Awarded by Australian National Health and Medical Research Council

Funding Acknowledgements

This research was supported by Project Grant GNT1104502 from the Australian National Health and Medical Research Council. J.A. W. was the recipient of an Australian Postgraduate Award. We thank the CSIRO Collaborative Crystallization Centre (, Melbourne, Australia, for the crystallization experiments. X-ray diffraction experiments were undertaken on the MX beamlines at the Australian Synchrotron, part of ANSTO.