* protein selection definition
*

define prot sele ( segid  prot) end
define water sele ( segid  solv) end
define nonh sele ( .not. hydrogen ) end
define trace sele ( type ca ) end
define back sele ( type n .or. type ca .or. type c ) end
define main sele ( type n .or. type ca .or. type c .or. type o) end
define side sele ( (.not. main) ) end