6QEQ

PcfF from Enterococcus faecalis pCF10

Summary for 6QEQ

• Entry DOI: 10.2210/pdb6qeq/pdb
• Descriptor: PcfF (2 entities in total)
• Functional Keywords: accessory factor, dna binding protein
• Biological source: Enterococcus faecalis
• Total number of polymer chains: 4
• Total formula weight: 56327.23

Authors

Rehman, S.,Berntsson, R.P.A. (deposition date: 2019-01-08, release date: 2019-05-01, Last modification date: 2024-11-20)

Primary citation

Rehman, S.,Li, Y.G.,Schmitt, A.,Lassinantti, L.,Christie, P.J.,Berntsson, R.P.
Enterococcal PcfF Is a Ribbon-Helix-Helix Protein That Recruits the Relaxase PcfG Through Binding and Bending of the oriT Sequence.
Front Microbiol, 10:958-958, 2019

PubMed Abstract: The conjugative plasmid pCF10 from encodes a Type 4 Secretion System required for plasmid transfer. The accessory factor PcfF and relaxase PcfG initiate pCF10 transfer by forming the catalytically active relaxosome at the plasmid's origin-of-transfer () sequence. Here, we report the crystal structure of the homo-dimeric PcfF, composed of an N-terminal DNA binding Ribbon-Helix-Helix (RHH) domain and a C-terminal stalk domain. We identified key residues in the RHH domain that are responsible for binding pCF10's sequence , and further showed that PcfF bends the DNA upon binding. By mutational analysis and pull-down experiments, we identified residues in the stalk domain that contribute to interaction with PcfG. PcfF variant proteins defective in or PcfG binding attenuated plasmid transfer , but also suggested that intrinsic or extrinsic factors might modulate relaxosome assembly. We propose that PcfF initiates relaxosome assembly by binding and inducing DNA bending, which serves to recruit PcfG as well as extrinsic factors necessary for optimal plasmid processing and engagement with the pCF10 transfer machine.

PubMed: 31134011
DOI: 10.3389/fmicb.2019.00958

Experimental method

X-RAY DIFFRACTION (1.9 Å)