cua-enable-cua-keys

cua-enable-cua-keys is a variable defined in `cua-base.el'.
Its value is

t

Documentation:
Enable using C-z, C-x, C-c, and C-v for undo, cut, copy, and paste.
If the value is t, these mappings are always enabled. If the value is
`shift', these keys are only enabled if the last region was marked with
a shifted movement key. If the value is nil, these keys are never
enabled.

You can customize this variable.