Transcription is the re-encoding of the information in a DNA gene into a complementary RNA sequence, carried out by RNA polymerase, which recognizes a promoter to initiate, unwinds the duplex, and synthesizes RNA in the 5'→3' direction using one strand as template until a terminator signal releases it. Because synthesis is templated on one strand, the resulting transcript reproduces the sequence of the opposite (coding) strand with uracil substituting for thymine. In prokaryotes the transcript is directly translatable messenger RNA, whereas in eukaryotes transcription yields pre-mRNA that must undergo nuclear processing — addition of a modified-guanine 5' cap, addition of a poly-A tail, and splicing out of introns to join the exons — before the mature mRNA exits the nucleus for translation. The topic belongs to molecular biology as the first stage of the central dogma of gene expression.
Transcription is the re-encoding of the information in a DNA gene into a complementary RNA sequence, carried out by RNA polymerase, which recognizes a promoter to initiate, unwinds the duplex, and sy…