RPB3, RPB5, and RPB7 interact with themselves to form homodimers, and RPB3 and RPB5 together are able to contact all of the other RPB subunits, except RPB9.
RPB3, RPB5, e RPB7 interaccionan con outras moléculas iguais para formar homodímeros, e RPB3 e RPB5 xuntos poden contactar con todas as outras subunidades RPB, excepto con RPB9.