Transcriptional activity of a complex of wheat RNA polymerase II and nonhistone chromosomal protein (NHCP)

A protein stimulating RNA polymerase activity that has been isolated and partially characterized previously (Walerych, W., Fabisz-Kijowska, A. et al., 1982, Phytochemistry, 21, 1495-1507) was subjected to investigations on its possible involvement in transcription process. Affinity chromatography revealed that this protein strongly binds to RNA polymerase-Sepharose column. The NHCP protects the enzyme against thermal inactivation, while the polymerase stabilizes the NHCP and maintains its ability to stimulate DNA transcription. The NHCP increases the affinity of RNA polymerase to DNA. Upon its addition, longer transcripts are obtained when a zein gene is used as a template for in vitro transcription. The RNA polymerase-NHCP complex formed has greater affinity to DNA than free enzyme. This seems to be due to enhanced sensitivity of bound enzyme to signals encoded in DNA sequences.