Exon-intron organization of Schizosaccharomyces pombe genes rpb10⁺ and rpc10⁺ encoding minisubunits of nuclear RNA polymerases I-III

The exon-intron structure and general organization were elucidated for genes encoding two smallest subunits, Rpb10 and Rpc10, constituents of all the three nuclear RNA polymerases of fission yeast Schizosaccharomyces pombe. Both structural genes have discontinuous sequences: a 53-bp intron was found in rpc10⁺, and 316- and 63-bp introns in rpb10⁺. The comparison of these genes with those for other common subunits (rpb5⁺, rpb6⁺, rpb8⁺) and the fet5⁺ gene (genetic partner of rpb10⁺) revealed structural similarly of the translation initiation sites of these genetic determinants of the Sz. pombe transcriptional machinery. The coordination of the synthesis of the common subunits of RNA polymerases I-III of Sz. pombe is suggested to take place meainly at the translation initiation stage.