EC 3.6.1.41     
Accepted name: bis(5′-nucleosyl)-tetraphosphatase (symmetrical)
Reaction: P1,P4-bis(5′-adenosyl) tetraphosphate + H2O = 2 ADP
Other name(s): diadenosinetetraphosphatase (symmetrical); dinucleosidetetraphosphatasee (symmetrical); symmetrical diadenosine tetraphosphate hydrolase; adenosine tetraphosphate phosphodiesterase; Ap4A hydrolase; bis(5′-adenosyl) tetraphosphatase; diadenosine tetraphosphate hydrolase; diadenosine polyphosphate hydrolase; diadenosine 5′,5′′′-P1,P4-tetraphosphatase; diadenosinetetraphosphatase (symmetrical); 1-P,4-P-bis(5′-nucleosyl)-tetraphosphate nucleosidebisphosphohydrolase
Systematic name: P1,P4-bis(5′-nucleosyl)-tetraphosphate nucleosidebisphosphohydrolase
Comments: Also acts on bis(5′-guanosyl) tetraphosphate and bis(5′-adenosyl) pentaphosphate and, more slowly, on some other polyphosphates, forming a nucleoside bisphosphate as one product in all cases [cf. EC 3.6.1.17 bis(5′-nucleosyl)-tetraphosphatase (asymmetrical)].
References:
1.  Barnes, L.D. and Culver, C.A. Isolation and characterization of diadenosine 5′,5′′′-P1,P4-tetraphosphate pyrophosphohydrolase from Physarum polycephalum. Biochemistry 21 (1982) 6123–6128. [PMID: 6295456]
2.  Guranowski, A., Jakubowski, H. and Holler, E. Catabolism of diadenosine 5′,5′′′-P1,P4-tetraphosphate in procaryotes. Purification and properties of diadenosine 5′,5′′′-P1,P4-tetraphosphate (symmetrical) pyrophosphohydrolase from Escherichia coli K12. J. Biol. Chem. 258 (1983) 14784–14789. [PMID: 6317672]
[EC 3.6.1.41 created 1986]