The largest subunit of mouse RNA polymerase II (RPB1) functionally substituted for its yeast counterpart in vivo

RNA Polymerase II Holoenzymes and Subcomplexes

“…Core Pol II molecules purified from a wide range of eukaryotes have conserved subunit structure and sequence. Moreover, many yeast Pol II subunit genes can be replaced with their mammalian counterparts in living cells without deleterious effects on cell function (22)(23)(24)(25)(26). This level of functional conservation is remarkable considering the thousands of protein coding genes that must be expressed appropriately for normal cellular function and viability.…”