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Updated: Aug 16, 2026

Chromatin Immunoprecipitation Assay for the Identification of Arabidopsis Protein-DNA Interactions In Vivo
Published on: January 14, 2016
Arabidopsis expresses two genes that encode polypeptides similar to the yeast RNA polymerase I and III AC40 subunit
T Ulmasov1, R M Larkin, T J Guilfoyle
1Department of Biochemistry, University of Missouri, Columbia 65211, USA.
Abstract:
A 40-kDa subunit in eukaryotic RNA polymerases (Pol) I and III (e.g., yeast yAC40) is related in a part of its aa sequence to the alpha subunit of prokaryotic Pol and to a 35-44-kDa subunit in Pol II (e.g., yeast yB44). We have cloned two cDNAs, AtRPAC42 and AtRPAC43, from an Arabidopsis thaliana (At) (ecotype Columbia) lambda Yes expression library that encode Pol I and III subunits related to yAC40. The aa sequences derived from the cDNA clones were found to be 72% identical to each other and 40% identical to yeast Pol I and III subunits yAC40, but only 30% identical to yeast Pol II subunit yB44. While most other nuclear Pol genes identified to date are single-copy genes, two genes encode 42 and 43-kDa subunits of At Pol I and/or III. A 42-kDa subunit with identical mobility in SDS-PAGE to the aAC42 in vitro translated subunit is found in Pol III purified from At suspension culture cells.
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