How to select sequences using substrings from several dictionaries

Question

I have four dictionaries that contain substrings:

fw1={\'PLAU_fw1\':\'CCCFFF\',\'EPCAM_fw1\':\'GGGTTT\',\'MIF_fw1\':\'HHHFFF\'}
fw1_rc={\'PLAU_fw1_rc\':\'cccf