Fig. 2: The S. aureus MecA crown.

a Model of the MecA C-terminal domain (CTD, in gold) sandwiched between two ClpC NTDs and one MD. Comparison between the crystal structure of B. subtilis ClpC in complex with MecA (pdb:3xpg) and the one from S. aureus solved in this study (pdb:9goq). b AlphaFold (AF) prediction of one monomer of S. aureus MecA showing a high confidence score for the NTD and the CTD. c Comparison of the AF prediction with known experimental structures of MecA NTD (in blue; pdb: 2mk6) and CTD (in gold). d AF predictions of MecA alone or with ClpC NTDs with 1:1 or 2:2 stoichiometry (see Figshare chimerax session MecA-ClpC_AF_models.cxs https://doi.org/10.1101/2025.06.06.658286) docked into the cryo-EM C6 MecA crown. Some models are compatible with the hexameric assembly and have the MecA NTD (in blue) placed toward the axial entrance of the ClpC chamber or outside the ring. e AF predictions of MecA/ClpC dimers docked into the low-resolution unsymmetrised map of the MecA crown.