SUPERFAMILY 1.75 HMM library and genome assignments server

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SinR repressor dimerisation domain-like superfamily

SCOP classification
Root:   SCOP hierarchy in SUPERFAMILY [ 0] (11)
Class:   All alpha proteins [ 46456] (284)
Fold:   Dimerisation interlock [ 47405] (4)
Superfamily:   SinR repressor dimerisation domain-like [ 47406]
Families:   SinR repressor dimerisation domain-like [ 47407] (2)

Superfamily statistics
Genomes (79) Uniprot 2018_03 genome PDB chains (SCOP 1.75)
Domains 231 1,796 2
Proteins 231 1,796 2

Functional annotation
General category General
Detailed category Protein interaction

Function annotation of SCOP domain superfamilies

InterPro annotation
Cross references IPR010981 SSF47406 Protein matches

The SinR repressor is part of a group of Sin (sporulation inhibition) proteins in Bacillus subtilis that regulate the commitment to sporulation in response to extreme adversity [PubMed9799632]. SinR is a tetrameric repressor protein that binds to the promoters of genes essential for entry into sporulation and prevents their transcription. This repression is overcome through the activity of SinI, which disrupts the SinR tetramer through the formation of a SinI-SinR heterodimer, thereby allowing sporulation to proceed. The SinR structure consists of two domains: a dimerisation domain stabilised by a hydrophobic core, and a DNA-binding domain that is identical to domains of the bacteriophage 434 CI and Cro proteins that regulate prophage induction. The dimerisation domain is a four-helical bundle formed from two helices from the C-terminal residues of SinR and two helices from the central residues of SinI. These regions in SinR and SinI are similar in both structure and sequence. The interaction of SinR monomers to form tetramers is weaker than between SinR and SinI, since SinI can effectively disrupt SinR tetramers.

This entry represents the dimerisation domain in both SinI and SinR proteins.

InterPro database

PDBeMotif information about ligands, sequence and structure motifs
Cross references PDB entries
Ligand binding statistics
Nucleic-acid binding statistics
Occurrence of secondary structure elements
Occurrence of small 3D structural motifs

PDBeMotif resource

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Internal database links

Browse genome assignments for this superfamily. The SUPERFAMILY hidden Markov model library has been used to carry out SCOP domain assignments to all genomes at the superfamily level.

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

Browse and view proteins in genomes which have different domain combinations including a SinR repressor dimerisation domain-like domain.

Examine the distribution of domain superfamilies, or families, across the major taxonomic kingdoms or genomes within a kingdom. This gives an immediate impression of how superfamilies, or families, are restricted to certain kingdoms of life.

Explore domain occurrence network where nodes represent genomes and edges are domain architectures (shared between genomes) containing the superfamily of interest.

There are 2 hidden Markov models representing the SinR repressor dimerisation domain-like superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be inspected.

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