+def dock_box(file):
+ import math
+ coord = list()
+ for line in file:
+ if line[0:6] == 'ATOM ' and line[13:15] == 'CA':
+ x=float(line[30:38])
+ y=float(line[38:46])
+ z=float(line[46:54])
+ coord.append([x, y, z])
+ if line[0:3] == 'END':
+ break
+ maxd=0
+ l=len(coord)
+ for i in xrange(l):
+ for j in xrange(i+1,l):
+ p1=coord[i]
+ p2=coord[j]
+ d=(p1[0]-p2[0])**2 + (p1[1]-p2[1])**2 + (p1[2]-p2[2])**2
+ if d > maxd:
+ maxd=d
+ return math.sqrt(maxd)
+
+