  A gauged version of Berkovits twistor string theory featuring the particle
content of N=8 supergravity was suggested by Abou-Zeid, Hull and Mason. The
equations of motion for a particular multiplet in the modified theory are
examined on the level of basic twistor fields and thereby shown to imply the
vanishing of the negative helicity graviton on-shell. Additionally, the
restrictions emerging from the equation of motion for the new gauge field
\bar{B} reveal the chiral nature of interactions in theories constructed in
this manner. Moreover, a particular amplitude in Berkovits open string theory
is shown to be in agreement with the corresponding result in Einstein gravity.
