Cloning and sequence determination of the Schizosaccharomyces pombe rpb2 gene encoding the subunit 2 of RNA polymerase II

摘要

The gene, rpb2, encoding the second largest subunit, subunit 2, of RNA polymerase II has been cloned from Schlzosaccharomyces pombe using the corresponding gene, RPB2, of Saccharomyces cerevisiae as a probe for cross-hybridization. We have determined the complete nucleotide sequence of rpb2, and parts of the PCR-amplifled rpb2 cDNA. The predicted coding sequence of a polypeptide of 1210 amino acid residues with a calculated molecular weight of 138 kilodaltons was interrupted by a short intron. The overall amino acid sequence homology of the S.pombe subunit 2 is 68, 62 and 62% with the corresponding protein from S.cerevisiae, D.melanogaster and H.saplens, respectively. Southern analysis of the genomic DNA digested with various restriction enzymes showed that rpb2 was present as a single copy in the S.pombe genome. Northern analysis showed that the transcript of rpb2 was about 4 kb in length.