Constructing a model assembly line
A model of an assembly line composed of α-δ modules was constructed
using the structures from the ESPript analysis. Domains were relatively
positioned with PyMOL and polyalanine loops were built with Coot[18,
19]. The relative orientations of the domains were acquired from
various crystal structures[20-22]; however, a 7-Å resolution
electron microscopy reconstruction of a β-module with traditional
boundaries from the pikromycin PKS shows a conformation of AT that is
much closer to ACP and may be more accurate [8]. The coordinates of
the model assembly line shown here can be freely downloaded from
http://keatinge-clay.cm.utexas.edu/research/.