L-tyrosyl-[protein] + GTP => O-(5'-guanylyl)-L-tyrosyl-[protein] + diphosphate
l-tyrosyl-[protein] + gtp => o-(5'-guanylyl)-l-tyrosyl-[protein] + diphosphate
L-tyrosyl-[protein] + GTP => O-(5'-guanylyl)-L-tyrosyl-[protein] + diphosphate
l-tyrosyl-[protein] + gtp => o-(5'-guanylyl)-l-tyrosyl-[protein] + diphosphate