GMP + GTP + 2 H(+) => P(1),P(4)-bis(5'-guanosyl) tetraphosphate + H2O
gmp + gtp + 2 h(+) => p(1),p(4)-bis(5'-guanosyl) tetraphosphate + h2o
GMP + GTP + 2 H(+) => P(1),P(4)-bis(5'-guanosyl) tetraphosphate + H2O
gmp + gtp + 2 h(+) => p(1),p(4)-bis(5'-guanosyl) tetraphosphate + h2o