  The photoproduction of pion off nucleon is investigated within a dynamical
coupled-channels approach based on the Juelich pi-N model, which has been quite
successful in the description of pi-N to pi-N scattering for center-of-mass
energies up to 1.9 GeV. The full pion photoproduction amplitude is constructed
to satisfy the generalized Ward-Takahashi identity and hence, it is fully gauge
invariant. The calculated differential cross sections and photon spin
asymmetries up to 1.65 GeV center-of-mass energy for the reactions gamma p to
pi^+ n, gamma p to pi^0 p and gamma n to pi^- p are in good agreement with the
experimental data.
