1.   The functional link for this class of proteins may not be their own protein sequence, but rather the nucleic acid structures recognized by their binding domains.

2.   The metal binding domain is also implicated in determining the sequence specificity since the DNA cleavage pattern is not affected by its distance from the bithiazole portion.

3.   Variations in the metal binding domain also alter the cleavage specificity.

4.   The binding domain on the mouse leukemia virus is relatively generic, Kim said, so that the virus can bind to the receptors on most rodent cells.