Figure 4: M1 site affects the stability of the PfTET3 oligomeric and dimeric interfaces.
From: Tuned by metals: the TET peptidase activity is controlled by 3 metal binding sites
On the top, the purple ellipse in the dodecamer highlights the oligomeric interface (formed by subunits purple and cyan) and the golden ellipse highlights the dimeric interface (formed by subunits gold and cyan). Left panel, inset of PfTET3 oligomeric interface (purple and cyan subunits). M1 and M2 sites are represented as a blue and a red sphere, respectively. The M1 coordinating residue, Glu208, lay on a loop that hosts Gln206, Arg212 (cyan). These residues are involved in H-bonding (represented by dashed lines) with Pro257, Asn292 and Gln295 of the adjacent subunit (purple). Additionally, Phe219 establishes π-stacking interactions with Arg298 of the adjacent subunit. Noteworthy, such interface is repeated 12 times in the dodecamer. Right panel, inset of PfTET3 dimeric interface (golden and cyan subunits). His314 coordinating the M1 site is close to the PfTET3 dimeric interface. In particular, Arg311 and Tyr312 are involved in salt bridges (represented with dashed lines) with Asp137 of the adjacent subunit. Noteworthy, each dimeric interface contain two copies of such interactions due to the 2-fold symmetry of the dimeric interface.
