VP7 is a glycoprotein that forms the outer surface of the virion. Gp64 is a homotrimeric membrane glycoprotein which is polarly present on the rod-shaped virion. This virus particle matures into brick-shaped intracellular mature virion (IMV). The protein aligns and the brick-shaped envelope of the intracellular enveloped virion. There are spikes made of glycoprotein protruding from each virion. The core of the virion consists of helically arranged ribonucleoprotein. Fusion proteins and attachment proteins appear as spikes on the virion surface. It is cleaved by virus encoded protease, releasing products found in the infectious virion. There are six viral proteins (VPs) that form the virus particle (virion). VP2 forms the core layer of the virion and binds the RNA genome. There are at least two unglycosylated membrane proteins in the outer envelope of the virion. "Pol" is the domain that encodes the virion protease. Theoretically, any possible HIV vaccine must inhibit or stop the HIV virion replication cycle. This hybrid virion then infects a new cell where it undergoes replication. Archaea also employ this mechanism of virion release.