  In stacks of two-dimensional crystals, mismatch of their lattice constants
and misalignment of crystallographic axes lead to formation of moir\'{e}
patterns. We show that moir\'{e} superlattice effects persist in twisted
bilayer graphene (tBLG) with large twists and short moir\'{e} periods. Using
angle-resolved photoemission, we observe dramatic changes in valence band
topology across large regions of the Brillouin zone, including the vicinity of
the saddle point at $M$ and across 3 eV from the Dirac points. In this energy
range, we resolve several moir\'{e} minibands and detect signatures of
secondary Dirac points in the reconstructed dispersions. For twists
$\theta>21.8^{\circ}$, the low-energy minigaps are not due to cone
anti-crossing as is the case at smaller twist angles but rather due to
moir\'{e} scattering of electrons in one graphene layer on the potential of the
other which generates intervalley coupling. Our work demonstrates robustness of
mechanisms which enable engineering of electronic dispersions of stacks of
two-dimensional crystals by tuning the interface twist angles. It also shows
that large-angle tBLG hosts electronic minigaps and van Hove singularities of
different origin which, given recent progress in extreme doping of graphene,
could be explored experimentally.
