InterPro : IPR001387

Name  Cro/C1-type helix-turn-helix domain Short Name  Cro/C1-type_HTH
Type  Domain Description  The cro/C1-type HTH domain is a DNA-binding, helix-turn-helix (HTH) domain ofabout 50-60 residues present in transcriptional regulators. The domain isnamed after the transcriptional repressors cro and C1 of temperatebacteriophages 434 and lambda, respectively. Besides in bacteriophages,cro/C1-type regulators are present in prokaryotes and in eukaryotes. Thehelix-turn-helix DNA-binding motif is generally located in the N-terminal partof these transcriptional regulators. The C-terminal part may contain anoligomerization domain, e.g. C1 repressors and CopR act as dimers, while SinRis a tetramer. The cro/C1-type HTH domain also occurs in combination with theTPR repeat and the C-terminal part of C-5 cytosine-specific DNA methylasescontains regions related to the enzymatic function.Several structures of cro/C1-type transcriptional repressors have beenresolved and their DNA-binding domain encompasses five alpha helices, of whichthe extremities are less conserved []. The helix-turn-helixmotif comprises the second and third helices, the third being called therecognition helix. The HTH is involved in DNA-binding into the major groove,where the recognition helix makes most DNA-contacts. The bacteriophagerepressors regulate lysogeny/lytic growth by binding with differentialaffinity to the operators. These operators show 2-fold symmetry and therepressors bind as dimers. Binding of the repressor to the operator positionsthe DNA backbone into a slightly bent twist [, ].

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

0 Contains

10 Found In

Id Name Short Name Type
IPR016429 Bifunctional transcriptional regulator NadR Bifunc_transcrip_reg_NadR Family
IPR016472 Transcription regulator, MJ0621, predicted Tscrpt_reg_MJ0621_prd Family
IPR016759 RapGH repressor RapGH_repressor Family
IPR017158 Transcription regulator, CBS domain-containing, predicted Tscrpt-reg_CBS-contain_prd Family
IPR022452 Zinc finger/helix-turn-helix protein, YgiT Znf/HTH_YgiT Family
IPR020886 Transcription regulator HTH, Cro/C1-type DNA-binding Tscrpt_reg_HTH_Cro/C1 Family
IPR017271 Transcription regulator HTH, MJ1545, predicted Tscrpt_reg_HTH_MJ1545_prd Family
IPR017507 Transcription regulator, HipB-like Tscrpt_reg_HipB-like Family
IPR013430 Toxin-antitoxin system, antidote protein, HigA Toxin_antidote_HigA Family
IPR013435 Mobile mystery protein A Mobile_mystery_prot_A Family

1 Parent Features

Id Name Short Name Type
IPR010982 Lambda repressor-like, DNA-binding domain Lambda_DNA-bd_dom Domain

2 Publications

First Author Title Year Journal Volume Pages
Aggarwal AK Recognition of a DNA operator by the repressor of phage 434: a view at high resolution. 1988 Science 242 899-907
Steinmetzer K CopR binds and bends its target DNA: a footprinting and fluorescence resonance energy transfer study. 2002 Nucleic Acids Res 30 2052-60

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)