Pathways & interactions
Transcription elongation factor GreA/GreB, C-terminal domain superfamily (IPR036953)
Short name: GreA/GreB_C_sf
- Transcription elongation factor, GreA/GreB, C-terminal (IPR001437)
- Transcription elongation factor GreB (IPR006358)
- Transcription elongation factor GreA (IPR006359)
- Transcription elongation factor GreA/GreB family (IPR023459)
- Transcription elongation factor GreA/GreB (IPR028624)
- Regulator of nucleoside diphosphate kinase (IPR028625)
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.
GreA and GreB are made up of two domains, each comprising about half of the protein. The C-terminal domain consists primarily of an alpha helix cradled by a five-strand beta-sheet [PMID: 7854424].
- G3DSA:18.104.22.168 (G3DSA:22.214.171.124)