HUMAN RNA-POLYMERASE-II SUBUNIT HRPB14 IS HOMOLOGOUS TO YEAST RNA POLYMERASE-I, POLYMERASE-II AND POLYMERASE-III SUBUNITS (AC19 AND RPB11) AND IS SIMILAR TO A PORTION OF THE BACTERIAL RNA-POLYMERASE-ALPHA SUBUNIT

The cDNA cloning of the human polII 14-kDa subunit, hRPB14, and the comparison of its aa sequence with those of other pol subunits are described. The aa sequence of hRPB14 has homology to yeast polII subunit RPB11 (44%), to a common subunit of yeast polI and polIII AC19 (24%) and to a Caenorhabditis elegnns sequence (33%). hRPB14 contains a 19-aa motif, located in its N terminus, which was also found in human polII 33-kDa subunit hRPB33, yeast pol subunits (AC40, AC19, RPB3 and RPB11), and in the bacterial pola subunit, which was involved in subunit assembly. This motif was also conserved in the conjugation-specific gene products of Tetrahymena (CnjC), Merchantia polymorpha chloroplast DNA (RNLVA) and C. elegans DNA (CEF58A4; deduced from the nucleotide sequence and of unknown function). The evolutionary emergence of a probable eukaryotic heterodimer, hRPB14/hRPB33, from a prokaryotic homodimer, a(2), is hypothesized.