  The contribution of virtual s-channel Kaluza-Klein (KK) gravitons to high
energy scattering of the SM fields in the Randall-Sundrum (RS) model with two
branes is studied. The small curvature option of the RS model is considered in
which the KK gravitons are narrow low-mass spin-2 resonances. The analytical
tree-level expression for a process-independent gravity part of the scattering
amplitude is derived, accounting for nonzero graviton widths. It is shown that
one cannot get a correct result, if a series of graviton resonances is replaced
by a continuous mass distribution, in spite of the small graviton mass
splitting. Such a replacement appeared to be justified only in the
trans-Planckian energy region.
