tokens: Computer analysis revealed that the human protein P1 sequence corresponding to amino acid residues within the N - terminal RNA binding domain displays high homology ( greater than 54 % identity ; 61 to 94 % similarity ) with two animal virus proteins which possess RNA binding activity ( vaccinia virus E3L ; rotavirus VP2 ) and two proteins of unknown function ( murine TIK ; rotavirus NS34 ) , but which are likely RNA binding proteins .