New paper on pSK41 Cop published in Plasmid

So excited to tell you about our latest paper published in Plasmid!

The analysis of the crystal structure in this paper was completed by Faith Northern VC ’22, 4th in author list, as part of her Vassar College senior biochemistry research! Congrats!

Faith Northern VC ’22

Link to paper:,3Mq7BJX

Paper summary:

We study conjugative plasmid transfer (CPT) as these plasmids often carry antibiotic resistance. To better understand CPT we probe structure & function of other plasmid-encoded proteins.

For e.g resistance to penicillins, & vancomycin have been found on the pSK41/pGO1-family of conjugative plasmids. pSK41/pGO1-family plasmids also encode the conserved gene orf86. We found that the orf86 protein can repress transcription of replication protein Rep.

orf86 is a cryptic regulator of copy number, so we named it Cop. We determined the crystal structure of Staphylococcus aureus pSK41 Cop. Together with binding data, it revealed a possible tetrameric binding mode (dimer of dimers) to the Rep promoter site on the plasmid.

Figure 3, Sarosh et. al 2023

We are grateful to our collaborators in the Firth Lab at the University of Sydney and the Redinbo Lab at the University of North Carolina Chapel Hill (UNC-CH), as this work was started during Dr. McLaughlin’s postdoctoral work at UNC-CH.