We study the crystal of quantum nilpotent subalgebra of UqpDnq associated to a maximal Levi subalgebra of type An´1. We show that it has an affine crystal structure of type D p1q n isomorphic to a limit of perfect Kirillov-Reshetikhin crystal B n,s for s ě 1, and give a new polytope realization of B n,s . We show that an analogue of RSK correspondence for type D due to Burge is an isomorphism of affine crystals and give a generalization of Greene's formula for type D.