  Revised analysis of Sigma beam asymmetry for eta photoproduction off the free
proton from GRAAL is presented. New analysis reveals a narrow structure near W
~1.685 GeV. We describe this structure by the contribution of a narrow
resonance with quantum numbers P_{11}, or P_{13}, or D_{13}. Being considered
together with the recent observations of a bump-like structure at W~1.68 GeV in
the quasi-free eta photoproduction off the neutron, this result provides an
evidence for a narrow (Gamma < 25 MeV) N*(1685) resonance. Properties of this
possible new nucleon state, namely the mass, the narrow width, and the much
stronger photocoupling to the neutron, are similar to those predicted for the
non-strange member of anti-decouplet of exotic baryons.
