FIG 6.

Difference in the C-terminal extensions of the subunits γ between the MCR type I from M. marburgensis, MCR type II from M. wolfeii, and MCR type III from M. thermolithotrophicus. (A) Surface representation of subunits α (light green), β (light purple), and β′ (cyan) and the C-terminal helix of subunit γ: γ8 in MCR type I and γ8 and γ9 in MCR types II and III (orange). The residues involved in hydrogen bonding and salt bridges are highlighted as a stick model; residues involved in hydrophobic/van der Waals interactions are shown only for subunit γ to avoid overcrowding. (B) The same representation as in panel A but with a focus on the conservation of the interacting residues (perfectly conserved, green; highly conserved, dark blue; partially conserved, pink; and not conserved, yellow).