DP is used to connect possessive determiners to gerunds in cases
where the gerund is taking its normal complement: 

                 +----------Ss*g----+
                 +----TOo--+        |
         +---DP--+-O---+   |        |
         |       |     |   |        |
	Your telling Jane to leave was a mistake

See "Ss#g: Gerunds: The Complement / No Determiner Case."