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SspB-like superfamily
SCOP classification
Superfamily statistics
Functional annotation
| General category | Regulation |
| Detailed category | Other regulatory function |
Document: Function annotation of SCOP domain superfamilies
InterPro annotation
| Cross references | IPR007481 SSF101738 Protein matches |
| Abstract | Escherichia coli stringent starvation protein B (SspB), is thought to enhance the specificity of degradation of tmRNA-tagged proteins by the ClpXP protease. The tmRNA tag, also known as ssrA, is an 11-aa peptide added to the C terminus of proteins stalled during translation, targets proteins for degradation by ClpXP and ClpAP. SspB is a cytoplasmic protein that specifically binds to residues 1-4 and 7 of the tag. Binding of SspB enhances degradation of tagged proteins by ClpX, and masks sequence elements important for ClpA interactions, inhibiting degradation by ClpA [ 11535833]. However, more recent work has cast doubt on the importance of SspB in wild-type cells [ 11810257]. SspB is encoded in an operon whose synthesis is stimulated by carbon, amino acid, and phosphate starvation. SspB may play a special role during nutrient stress, for example by ensuring rapid degradation of the products of stalled translation, without causing a global increase in degradation of all ClpXP substrates [ 11009422]. |
InterPro database
PDBeMotif information about ligands, sequence and structure motifs
PDBeMotif resource
Jump to [ Top of page · SCOP classification · InterPro annotation · PDBeMotif links · Functional annotation ]
Internal database links
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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.
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Alignments of sequences to 3 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.
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Browse and view proteins in genomes which have
different domain combinations including a SspB-like domain.
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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.
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Explore domain occurrence network where nodes represent genomes and edges are domain architectures (shared between genomes) containing the superfamily of interest.
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There are 3 hidden Markov models representing the SspB-like superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be inspected.
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Jump to [ Top of page · SCOP classification · InterPro annotation · PDBeMotif links · Functional annotation · Internal database links ]
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