Protein Domain : IPR018335

Type:  Conserved_site Name:  Transcription regulator HTH, Crp-type, conserved site
Description:  The crp-type HTH domain is a DNA-binding, winged helix-turn-helix (wHTH) domain of about 70-75 amino acids present in transcription regulators of the crp-fnr family, involved in the control of virulence factors, enzymes of aromatic ring degradation, nitrogen fixation, photosynthesis, and various types of respiration. The crp-fnr family is named after the first members identified in Escherichia coli: the well characterised cyclic AMP receptor protein CRP or CAP (catabolite activator protein) and the fumarate and nitrate reductase regulator Fnr. crp-type HTH domain proteins occur in most bacteria and in chloroplasts of red algae. The DNA-binding HTH domain is located in the C-terminal part; the N-terminal part of the proteins of the crp-fnr family contains a nucleotide-binding domain and a dimerisation/linker helix occurs in between. The crp-fnr regulators predominantly act as transcription activators, but can also be important repressors, and respond to diverse intracellular and exogenous signals, such as cAMP, anoxia, redox state, oxidative and nitrosative stress, carbon monoxide, nitric oxide or temperature []. The structure of the crp-type DNA-binding domain shows that the helices (H) forming the helix-turn-helix motif (H2-H3) are flanked by two beta-hairpin (B) wings, in the topology H1-B1-B2-H2-H3-B3-B4. Helix 3 is termed the recognition helix, as in most wHTHs it binds the DNA major groove [, , ]. Some proteins known to contain a Crp-type HTH domain: E. coli crp (also known as cAMP receptor), a protein that complexes with cAMP and regulates the transcription of several catabolite-sensitive operons. E. coli fnr, a protein that activates genes for proteins involved in a variety of anaerobic electron transport systems. Rhizobium leguminosarumfnrN, a transcription regulator of nitrogen fixation. Rhodobacter sphaeroides(Rhodopseudomonas sphaeroides) fnrL, a transcription activator of genes for heme biosynthesis, bacteriochlorophyll synthesis and the light-harvesting complex LHII. Rhizobiacae fixK, a protein that regulates nitrogen fixation genes, both positively and negatively. Lactobacillus caseifnr-like protein flp, a putative regulatory protein linked to the trpDCFBA operon. Cyanobacteria ntcA, a regulator of the expression of genes subject to nitrogen control. Xanthomonas campestrisclp, a protein involved in the regulation of phytopathogenicity. Clp controls the production of extracellular enzymes, xanthan gum and pigment, either positively or negatively. Short Name:  Tscrpt_reg_HTH_Crp-type_CS

0 Child Features

0 Contains

1 Cross References

Identifier
PS00042

3 Found Ins

DB identifier Type Name
IPR011991 Domain Winged helix-turn-helix DNA-binding domain
IPR012318 Domain Crp-type HTH domain
IPR022299 Family Transcription regulator, NtcA

3 GO Annotations

GO Term Gene Name
GO:0003700 IPR018335
GO:0006355 IPR018335
GO:0005622 IPR018335

3 Ontology Annotations

GO Term Gene Name
GO:0003700 IPR018335
GO:0006355 IPR018335
GO:0005622 IPR018335

0 Parent Features

0 Proteins

4 Publications

First Author Title Year Journal Volume Pages PubMed ID
            10550204
            11839496
            8441692
            11017196