  We study the supersymmetry generators Q, S on the 1-loop vectorless sector of
N=4 Super Yang-Mills, by reduction to the plane-wave matrix model. Using a
coherent basis in the su(2|2) sector, a comparison with the algebra given by
Beisert in nlin/0610017 is presented, and some parameters (up to one-loop) are
determined. We make a final comparison of these supercharges with the results
that can be obtained from the string action by working in the light-cone-gauge
and discretizing the string.
