  The five dimensional AGT correspondence implies the connection between the
q-deformed Virasoro block and the 5d Nekrasov partition function. In this
paper, we determine a q-deformation of the four-point block in the Coulomb gas
representation from the 5d Nekrasov function, and obtain an expression of the
q-deformed vertex operator. If we use only one kind of the q-vertex operators,
one of the insertion points of them must be modified in order to hold the 2d/5d
correspondence.
