Table 1.
Bending parameters determined with the program ARC_FIT.
The curvilinear helical axis
is calculated with CURVES, and bending of this
axis is analysed with ARC_FIT. This program allows to fit a
straight line, a plane, an arc, a kinked line, and a double kinked line
to the helical axis. Good fits are indicated by low values of
sigma2. An arc is fitted if there are at least
7 bp. A kinked line requires at least 8 bp, and the double
kinked line requires at least 13 bp. The geometrical parameters
are given for all models fitted, but they characterize the shape of the
helical axis only if the fit is good. See Help for further
explanations.