Figure 2.

Representation of the PLA₂-like protein iFace and proposed axes of movement. Sulphate ions are represented as orange spheres and compose a plane that indicates the PLA₂-like iFace (in a). N- and C-terminal residues compose this iFace, which includes a membrane docking site represented by green sticks in (a) that interacts with sulphates. In (b) the PLA₂-like monomer is represented by a grey cartoon with Cc7 represented as spheres. The axes are established by Cc7/98 as the origin and coloured black; by Cc7/108 as the X-axis and coloured magenta; by a perpendicular vector to the X-axis, in the plane composed by X-axis and Cc7/48 sphere, as the Y-axis and coloured dark blue; and the normal vector to the XY plane coloured vermilion. In (c–f) the two antiparallel helices are illustrated to indicate different orientations of monomer A (light blue) corresponding to monomer B; the calculated angles are shown in the box. Tilt is coloured in vermilion, twist in dark blue and roll in dark blue. In (c–f) monomer B, coloured in black, is close to the orientation of BnIV/myristic acid structure (PDB id: 3MLM), which is established as a reference to show a difference of 45° in each of the axes of movement. The axes in (d–f) are shown as illustrations of the rotation that describes monomer B in transparent black relative to the other monomer, which is not transparent.