Abstract:Saccharomyces cerevisiae is a classic model organism for studying the biochemical mechanisms of eukaryotic cells. Eukaryotes have three main types of RNA polymerases: RNA polymerase I (RNAPI), RNA polymerase II (RNAPII), and RNA polymerase III (RNAPIII). Among them, RNAPIII has the most complex structure, consisting of 17 subunits, and it is primarily responsible for the synthesis of transfer RNA (tRNA). Compared with RNAPII consisting of 12 subunits, RNAPIII contains a unique heterotrimer Rpc82/31/34 and a heterodimer Rpc53/37 which is homologous to the counterpart of RNAPI. This paper reviews the structures and functions of the specific heterotrimer and heterodimer in RNAPIII, aiming to lay a theoretical foundation for further studies on the modification mechanisms and assembly processes of specific subunits of RNAPIII in S. cerevisiae.