Thus, it is used in antiviral therapy. F. Transcription 1. RNA polymerase is to transcription what DNA polymerase is to replication except it does not require a primer. Signals in front of genes tells RNA polymerase where and when to start. All together the signals are called promoters.
Transcription factors bind to specific signals to promote or hinder RNA polymerase.
The best known transcription factors are proteins that bind steroid hormones and response elements in front of genes that are hormonally regulated. The product of transcription is a primary transcript. In eukaryotes the primary transcript must be capped, spliced and polyadenylated. G. Posttranscriptional modifications transform precursor messenger RNAs to mature mRNAs in the nucleus. Splicing takes place on spliceosomes containing snurps composed of snRNAs and spliceosome proteins.