sigma factor activity

Term ID

GO:0016987

Synonyms

• bacterial sigma factor activity
• core DNA-dependent RNA polymerase binding promoter specificity activity
• DNA-dependent RNA polymerase promoter selection factor
• plastid sigma factor activity
• promoter selection factor activity
• sigma transcription factor

Definition

Sigma factors act as the promoter specificity subunit of eubacterial and plant plastid multisubunit RNA polymerases, whose core subunit composition is often described as alpha(2)-beta-beta-prime. Although sigma does not bind DNA on its own, when combined with the core to form the holoenzyme, the sigma factor binds specifically to promoter elements. The sigma subunit is released once elongation begins.

References

Ontology

GO: Molecular Function    QuickGO    AmiGO