Figure 1. Schematic diagram showing three possible paths that the polypeptide
chain may follow in a two domain protein. a) This shows the simple case in which
the chain first passes through one domain and then the other. b) The chain runs
from the first domain into the second and then back into the first to complete
it. c) Same as b) except that after the chain completes the first domain
it passes back into the second to complete it.
