passages.id: split_4_test_2791_passage
passages.type: progene_text
passages.text: It is hypothesized that the ArdA protein forms two complexes with the type I restriction -- modification enzyme ( R2M2S ) : (1) with a specific region in the S subunit involved in contact with the sK site in DNA ; and ( 2 ) with a nonspecific region in the R subunit involved in DNA translocation and degradation by restriction endonucleases .