The distribution of mIMRs in the immature Gag protein [NCBI:1L6N, ]. MIMRs that are ≥ 50% symmetric are noticeably absent from some segments of the protein. These regions are characterized by a series of rdIMRs, arranged end-to-end (illustrated in black). The spans lacking mIMRs are highly reactive and mobile. The A3..C87 region of matrix undergoes structural transformation at several stages of the virion life cycle, and contains basic residues that target Gag to the plasma membrane , a calmodulin-binding motif  and a nuclear localization signal . The T204..E245 region of capsid includes the exposed loop on the virion core [8, 12], and the CypA binding site .