שעתוק

Transcription is the process of synthesizing RNA from a DNA template.

On the template DNA, the transcription pre-initiation complex assembles around the core promoter of a gene. The promoter includes the TATA box and an Initiator sequence. The general transcription factors bind at the TATA box, while the initiator sequence contains the transcription start site.

Once the necessary components are bound, the preinitiation complex unwinds a short stretch of the DNA upstream of the transcription start site. After that, the general transcription factors get dissociated from the strand and the RNA polymerase begins producing a new strand of mRNA.

Nucleotides are added one by one, and synthesis of the mRNA occurs in a five prime to three prime direction, reading from the template strand, except the thymidines are replaced by uridines.

This newly-created mRNA strand represents a copy of the information in the coding strand. The synthesis will continue until a termination sequence is encountered, which will release the newly-made mRNA.