Open AccessC25, an essential RNA polymerase III subunit related to the RNA polymerase II subunit RPB7.
Author(s) -
Parag P. Sadhale,
Nancy A. Woychik
Publication year - 1994
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.14.9.6164
Subject(s) - biology , rna polymerase i , rna polymerase ii , microbiology and biotechnology , rna polymerase iii , polymerase , small nuclear rna , transcription factor ii d , rna dependent rna polymerase , rna polymerase , specificity factor , rna polymerase ii holoenzyme , transcription (linguistics) , rna , biochemistry , gene , gene expression , promoter , linguistics , philosophy
We identified a partially sequenced Saccharomyces cerevisiae gene which encodes a protein related to the S. cerevisiae RNA polymerase II subunit, RPB7. Several lines of evidence suggest that this related gene, YKL1, encodes the RNA polymerase III subunit C25. C25, like RPB7, is present in submolar ratios, easily dissociates from the enzyme, is essential for cell growth and viability, but is not required in certain transcription assays in vitro. YKL1 has ABF-1 and PAC upstream sequences often present in RNA polymerase subunit genes. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis mobility of the YKL1 gene product is equivalent to that of the RNA polymerase III subunit C25. Finally, a C25 conditional mutant grown at the nonpermissive temperature synthesizes tRNA at reduced rates relative to 5.8S rRNA, a hallmark of all characterized RNA polymerase III mutants.