IIS should be installed on the Member server. There is no need of IIS on the DC if it does not have exchange on it.
Since the virtual directories are missing from the IIS, you will have to create the virtual directories.
first check in the ADISEDIT if you have the virtual directories present. if not then you can run the prepareAd and this will create the virtual directories. else you will have to uninstall the CAS role and reinstall the CAS role so that the virtual directores will be created in the IIS.