Transcription elongation factor GreA/GreB family (IPR023459)

Short name: Tscrpt_elong_fac_GreA/B_fam

Overlapping homologous superfamilies

Family relationships


Bacterial proteins GreA and GreB are necessary for efficient RNA polymerase transcription elongation past template-encoded arresting sites. Arresting sites in DNA have the property of trapping a certain fraction of elongating RNA polymerases that pass through, resulting in locked DNA/RNA/ polymerase ternary complexes. Cleavage of the nascent transcript by cleavage factors, such as GreA or GreB, allows the resumption of elongation from the new 3' terminus [PMID: 8431948, PMID: 7854424]. Escherichia coli GreA and GreB are sequence homologues and have homologues in every known bacterial genome [PMID: 12914698]. GreA induces cleavage two or three nucleotides behind the terminus and can only prevent the formation of arrested complexes while greB releases longer sequences up to eighteen nucleotides in length and can rescue preexisting arrested complexes. These functional differences correlate with a distinctive structural feature, the distribution of positively charged residues on one face of the N-terminal coiled coil. Remarkably, despite close functional similarity, the prokaryotic Gre factors have no sequence or structural similarity with eukaryotic TFIIS.

This entry represents the transcription elongation factor GreA/GreB family. In addition to GreA and GreB, it also includes regulator of nucleoside diphosphate kinase, which is an RNA polymerase-interacting protein that may act as an anti-Gre factor [PMID: 18760284].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0070063 RNA polymerase binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.