3.6.1.17 bis(5'-nucleosyl)-tetraphosphatase (asymmetrical); bis(5'-guanosyl)-tetraphosphatase; bis(5'-adenosyl)-tetraphosphatase; diguanosinetetraphosphatase (asymmetrical); dinucleosidetetraphosphatase (asymmetrical); diadenosine P1,P4-tetraphosphatase; din • • •