  A formalism based on a chiral quark model ($\chi$QM) approach complemented
with a one-gluon exchange model, to take into account the breakdown of the
$SU(6)\otimes O(3)$ symmetry, is presented. The configuration mixing of wave
functions for nucleon and resonances are derived. % With few adjustable
parameters, differential cross-section and polarized beam asymmetry for the
$\gamma p \to \eta p$ process are calculated and successfully compared with the
data in the centre-of-mass energy range from threshold up to 2 GeV. The known
resonances $S_{11}(1535)$, $S_{11}(1650)$, $P_{13}(1720)$, $D_{13}(1520)$, and
$F_{15}(1680)$, as well as two new $S_{11}$ and $D_{15}$ resonances are found
to be dominant in the reaction mechanism. Besides, connections among the
scattering amplitudes of the $\chi$QM approach and the helicity amplitudes, as
well as decay widths of resonances are established. Possible contributions from
the so-called "missing resonances" are investigated and found to be negligible.
