Purification tag of AcpSSA in the CoA-binding site. The symmetry-related trimer is shown in surface representation. The trimer of the asymmetric unit is shown in ribbon representation. The 24-residue purification tag (red) and residues 83–84 (black oval) that stabilize the α5′-helix of SYM C are shown. A dashed yellow oval visualizes the binding area of the P-pant portion of CoA.