SUPERFAMILY 1.73 HMM library and genome assignments server


GreA transcript cleavage protein, N-terminal domain superfamily

SCOP classification
Root:   SCOP hierarchy in SUPERFAMILY [ 0] (11)
Class:   All alpha proteins [ 46456] (258)
Fold:   Long alpha-hairpin [ 46556] (19)
  2 helices; antiparallel hairpin, left-handed twist
Superfamily:   GreA transcript cleavage protein, N-terminal domain [ 46557]
Families:   GreA transcript cleavage protein, N-terminal domain [ 46558]


InterPro annotation
Cross references IPR001437 SSF46557 Protein matches
Abstract 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 [PubMed8431948, PubMed7854424].

Escherichia coli GreA and GreB are sequence homologues and have homologues in every known bacterial genome [PubMed12914698]. 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.


InterPro database

Functional annotation
General category coiled coil
Detailed category This is a complex coiled arrangement. The details of which will appear on this page shortly (some coiled coil details are being checked before they are included on the site). If you want to see examples of the states please click here here. If you require further details urgently please contact Owen Rackham

Function annotation of SCOP domain superfamilies

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Internal database links

The SUPERFAMILY hidden Markov model library has been used to carry out SCOP domain assignments to all genomes at the superfamily level. Click on the 'Genome Assignments' icon above to view the genome assignments for this superfamily.


Alignments of sequences to

Alignments of sequences to 2 models in this superfamily are available by clicking on the superfamily level 'Alignments' icon above. PDB sequences less than 40% identical are shown by default, but any other sequences may be aligned. Select PDB sequences, genome sequences, or paste in or upload your own.


It is possible to browse and view the proteins in the genomes which have different combinations of domains including a GreA transcript cleavage protein, N-terminal domain domain. Click on the 'Domain Combinations' icon.


To view the distribution of domain superfamilies, or families, across the major taxonomic kingdoms or genomes within a kingdom click on the 'TaxViz' icon above. This gives an immediate impression of how superfamilies, or families, are restricted to certain kingdoms of life.


Undirected domain occurrence networks are available for all superfamilies. Nodes in these networks represent genomes. Connections between nodes represent the presence of domain architectures, which contain the superfamily of interest, in both genomes.

There are 2 hidden Markov models representing the GreA transcript cleavage protein, N-terminal domain superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be viewed by clicking on the icon above.


Jump to [ Top of page · SCOP classification · InterPro annotation · Functional annotation · Internal database links ]