HIV PR processes the Gag and Gag-Pol precursor proteins during the maturation stage of viral replication. PR releases itself and the individual proteins: MA, CA, NC, RT, IN and RH, as well as small, probably unstructured, spacer peptides sp1, sp2 and p6. The arrows indicate the cleavage sites. The maturation inhibitor, Bevirimat, targets the CA-sp1 cleavage site and cleavage of TF-PR at the N-terminus of PR is another potential target for novel inhibitors, as indicated by asterisks in Gag and Gag-Pol.
CA: Capsid; IN: Integrase; MA: Matrix; NC: Nucleocapsid; PR: Protease; RH: RNaseH; RT: Reverse transcriptase.