FIGURE 1: Schematic representation of retroviral Gag proteins. All retroviruses encode three main genes: gag, pol and env. The gag gene codes for the structural proteins of the virus. It is translated into a polyprotein that is then cleaved during viral maturation in orthoretroviruses into individual proteins as indicated in the key: matrix (MA, green); capsid (CA, red); nucleocapsid (NC, blue) and additional small proteins (purple and pink). The Gag protein of spumaretroviruses is not cleaved, shown in brown. The position of proline-rich late domain motifs which recruit the ESCRT pathway to facilitate viral release in late replication are indicated in yellow. The identified chromatin binding motifs are shown in light blue. The p12 amino acid sequence from the gammaretrovirus Mo-MLV is given, highlighting the motif in the NTD responsible for CA binding (in purple) and the CTD chromatin binding motif (in light blue). Abbreviations: PFV, prototypic foamy virus; HIV, human inmmunodeficiency virus; BLV, bovine leukemia virus; WDSV, walleye dermal sarcoma virus; RSV, Rous sarcoma virus; M-PMV, Mason Pfizer Monkey virus; MLV, murine leukemia virus.