  In this paper, we introduce a new model of deterministic Watson-Crick
automaton namely restricted deterministic Watson- Crick automaton which is a
deterministic Watson-Crick automaton where the complementarity string in the
lower strand is restricted to a language L. We examine the computational power
of the restricted model with respect to L being in different language classes
such as regular, unary regular, finite, context free and context sensitive. We
also show that computational power of restricted deterministic Watson- Crick
automata with L in regular languages is same as that of deterministic
Watson-Crick automata and that the set of all languages accepted by restricted
deterministic Watson-Crick automata with L in unary regular languages is a
proper subset of context free languages.
