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#DNA strand

2 public questions tagged with this topic.

Transcription Basics

The strand having same sequence as RNA (except T/U) is called

Nomenclature for DNA strands relative to transcription distinguishes informational equivalence. Template strand directly read by polymerase and complementary to RNA. Opposite strand contains sequence identical to RNA product except thymine replaces uracil, hence called coding, sense, or non-template strand. When gene sequence deposited in databases, coding strand displayed in 5' to 3' orientation matching mRNA for convenience interpreting codons. This strand does not contact catalytic center. Recognition that RNA equals coding sequence simplifies annotation of promoters, open reading frames, a

Ref: Alberts Chapter 6: Coding strand definition same as RNA; Watson Chapter 13 Coding vs non-template terminology

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Transcription Basics

Only one strand of DNA is used in transcription because it acts as

Despite double-stranded DNA chemically offering two complementary sequences, transcription uses only one as template to avoid production of overlapping complementary RNAs that would anneal into inert duplex. Within transcription bubble, polymerase binds template strand oriented 3' to 5' to synthesize RNA antiparallel, while coding non-template strand displaced. Template strand determination defined by promoter orientation and direction of polymerase binding. Only antisense strand read, also called template or transcribed strand, ensures mRNA sequence uniqueness. Using single strand prevents si

Ref: NCBI Biochemistry Transcription bubble template selection rationale; Lodish Chapter 8: One strand used as template mechanism

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