The pore surface of cholera toxin B₅

The pore surface of cholera toxin B₅. For clarity only a C_alpha trace is shown for the protein, which is colour coded by chain. Two orthogonal views are shown: on the left hand side the channel direction vector runs horizontal across the page whereas on the right the vector is out of the page. The pore surface as revealed by the capsule option of HOLE is shown as a dot surface. The surface is colour coded so that places where there is not sufficient room to accomodate a water molecule are coloured red, green shows where a single water molecule could be placed and blue where two water molecules side by side could be located. The yellow line marks the centre of the channel. Cholera toxin B₅ can be seen to have a regular and wide pore. This picture was produced with the aid of the programs quanta and qplot (part of the HOLE package). If you have a suitable viewer (see http://www.ch.ic.ac.uk/VRML/ for details) then have a look at the vrml version of this figure.

Oliver S. Smart (last modified 23/9/96)