  The RBC and UKQCD collaborations have been investigating hadron physics in
numerical lattice quantum chromodynamics (QCD) with (2+1) flavors of dynamical
domain wall fermions (DWF) quarks that preserves continuum-like chiral and
flavor symmetries. The strange quark mass is adjusted to physical value via
reweighting and degenerate up and down quark masses are set as light as
possible. In a recent study of nucleon structure we found a strong dependence
on pion mass and lattice spatial extent in isovector axialvector-current form
factors. This is likely the first credible evidence for the pion cloud
surrounding nucleon. Here we report the status of nucleon structure
calculations with a new (2+1)-flavor dynamical DWF ensembles with much lighter
pion mass of 180 and 250 MeV and a much larger lattice spatial exent of 4.6 fm.
A combination of the Iwasaki and dislocation-suppressing-determinant-ratio
(I+DSDR) gauge action and DWF fermion action allows us to generate these
ensembles at cutoff of about 1.4 GeV while keeping the residual breaking of
chiral symmetry sufficiently small. Nucleon source Gaussian smearing has been
optimized. Preliminary nucleon mass estimates are 0.98 and 1.05 GeV.
