Classification and structural organization of pbMRP. (A) Conserved domain database summary view of the domain model identifying ABCC specific NBDs within pbMRP. These domains are depicted by red boxes under the corresponding regions within the predicted protein sequence. (B) Graphical representation the pbMRP predicted topology generated by the TMHMM server. Results were also confirmed using the DAS server transmembrane prediction. Predicted transmembrane helices are depicted in red. (C) Diagram of pbMRP embedded in the membrane. The protein contains two TMDs and two ATP-binding NBDs represented by red cylinders and blue circles, respectively.