Interferon regulatory factor, DNA-binding domain
IPR001346
Definition
Viral infections induce the expression of type I interferons (IFN-alpha and IFN-beta) genes. The induction is due to the transcriptional activation of the IFN genes. Interferon regulatory factor I (IRF-1) is one of the transcription factors responsible for that activation. IRF-1 binds to an upstream regulatory cis element, known as the interferon consensus sequence (ICS), which is found in the promoters of type I IFN and IFN-inducible MHC class I genes. Interferon regulatory factor 2 (IRF-2) is a protein that also interacts with the ICS, but that does not function as an activator; rather, it suppresses the function of IRF-1 under certain circumstances PMID:2691585. These proteins share a highly conserved N-terminal domain of about 100 amino acid residues which is involved in DNA-binding and which contain five conserved tryptophans. This domain is known as a 'tryptophan pentad repeat' or a 'tryptophan cluster' and is also present in: Interferon consensus sequence binding protein (ICSBP) PMID:2111015, a transcription factor expressed predominantly in lymphoid tissues and induced by IFN-gamma that also binds to the ICS. Transcriptional regulator ISGF3 gamma subunit PMID:1630447. ISGF3 is responsible for the initial stimulation of interferon-alpha-responsive genes. It recognises and binds to the interferon-stimulated response element (ISRE) within the regulatory sequences of target genes. Interferon regulatory factor 3 (IRF-3). Interferon regulatory factor 4 (IRF-4) which binds to the interferon- stimulated response element (ISRE) of the MHC class I promoter. Interferon regulatory factor 5 (IRF-5). Interferon regulatory factor 6 (IRF-6). Interferon regulatory factor 7 (IRF-7). Gamma Herpesviruses vIRF-1, -2 and -3, proteins with homology to the cellular transcription factors of the IRF family PMID:10933732. Neither vIRF-1 nor vIRF-2 bind to DNA with the same specificity as cellular IRFs, indicating that if vIRFs are DNA-binding proteins, their binding has a pattern distinct from that of the cellular IRFs. Whether vIRF-3 can bind DNA with the same specificity as cellular IRFs is not known. The IRF tryptophan pentad repeat DNA-binding domain has an α/β architecture comprising a cluster of three α-helices (alpha1-alpha3) flanked on one side by a mixed four-stranded β-sheet (beta1-beta4). It forms a helix-turn-helix motif that binds to ISRE consensus sequences found in target promoters. Three of the tryptophan residues contact DNA by recognising a GAAA sequence PMID:9422515. This entry represents the IRF tryptophan pentad repeat DNA-binding domain.
9 human proteins with this domain
Each is a reviewed human protein in the Seroatlas serome and a potential autoantibody target; this domain groups them into one antibody-relevant category. Every entry links to its own record.
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