the presence of these conserved and essential subunits in all three nuclear rna polymerases and the absence of recognizable sequence motifs for dna and nucleoside triphosphate-binding indicate that the common subunits do not have a catalytic role but are important for a function shared by the rna polymerases such as transcriptional efficiency , nuclear localization , enzyme stability , or coordinate regulation of rrna , mrna , and trna synthesis .
C0035681
rna polymerases
C0040649
transcriptional