This domain is found in a bacterial family of spore coat proteins (PUBMED:1904442) as well as a family of secreted pili proteins involved in motility and biofilm formation (PUBMED:1904442).
This domain is found in protein U, a spore coat protein produced at the late stage of development of Myxococcus xanthus. Protein U is produced as a secretory precursor, pro-protein U, which is then secreted across the membrane to assemble on the spore surface [ (PUBMED:1904442) ]. This domain is also found in a number of the genes within a conserved polycistronic operon that encodes a novel chaperone-usher pili assembly system. Examples are CsuA/B of Acinetobacter baumannii, and the CsuA, CsuB and CsuE of Vibrio parahaemolyticus and the related genes of Yersinia pestis.
In A. baumannii, csuC and csuE are required in the early steps of the process that that leads to biofilm formation. The conservation of the genes and gene order among unrelated bacteria, suggests that the csu operon is widespread and is involved in surface pilus formation which allows the bacteria to form biofilms on abiotic surfaces, a property that may aid there survival in their natural environment [ (PUBMED:14663080) ].
Family alignment:
There are 7228 SCPU domains in 5693 proteins in SMART's nrdb database.
Click on the following links for more information.
Evolution (species in which this domain is found)
Taxonomic distribution of proteins containing SCPU domain.
This tree includes only several representative species. The complete taxonomic breakdown of all proteins with SCPU domain is also avaliable.
Click on the protein counts, or double click on taxonomic names to display all proteins containing SCPU domain in the selected taxonomic class.
Literature (relevant references for this domain)
Primary literature is listed below; Automatically-derived, secondary literature is also avaliable.
Attachment to and biofilm formation on abiotic surfaces by Acinetobacterbaumannii: involvement of a novel chaperone-usher pili assembly system.
Microbiology. 2003; 149: 3473-84
Display abstract
Acinetobacter baumannii causes severe infections in compromised patients,survives on abiotic surfaces in hospital environments and colonizesdifferent medical devices. In this study the analysis of the processesinvolved in surface attachment and biofilm formation by the prototypestrain 19606 was initiated. This strain attaches to and forms biofilmstructures on plastic and glass surfaces, particularly at the liquid-airinterface of cultures incubated stagnantly. The cell aggregates, whichcontain cell stacks separated by water channels, formed under differentculture conditions and were significantly enhanced under iron limitation.Electron and fluorescence microscopy showed that pili andexopolysaccharides are part of the cell aggregates formed by this strain.Electron microscopy of two insertion derivatives deficient in attachmentand biofilm formation revealed the disappearance of pili-like structuresand DNA sequencing analysis showed that the transposon insertionsinterrupted genes with the highest similarity to hypothetical genes foundin Pseudomonas aeruginosa, Pseudomonas putida and Vibrio parahaemolyticus.Although the products of these genes, which have been named csuC and csuE,have no known functions, they are located within a polycistronic operonthat includes four other genes, two of which encode proteins related tochaperones and ushers involved in pili assembly in other bacteria.Introduction of a copy of the csuE parental gene restored the adherencephenotype and the presence of pili on the cell surface of the csuE mutant,but not that of the csuC derivative. These results demonstrate that theexpression of a chaperone-usher secretion system, some of whose componentsappear to be acquired from unrelated sources, is required for piliformation and the concomitant attachment to plastic surfaces and theensuing formation of biofilms by A. baumannii cells.
Protein U, a late-developmental spore coat protein of Myxococcus xanthus,is a secretory protein.
J Bacteriol. 1991; 173: 3597-600
Display abstract
Protein U is a spore coat protein produced at the late stage ofdevelopment of Myxococcus xanthus. This protein was isolated fromdevelopmental cells, and its amino-terminal sequence was determined. Onthe basis of this sequence, the gene for protein U (pru) was cloned andits DNA sequence was determined, revealing an open reading frame of 179codons. The product from this open reading frame has a typical signalpeptide of 25 amino acid residues at the amino terminal end, followed byprotein U of 154 residues. This result indicates that protein U isproduced as a secretory precursor, pro-protein U, which is then secretedacross the membrane to assemble on the spore surface. This is in sharpcontrast to protein S, a major spore coat protein produced early indevelopment, which has no signal peptide, indicating that there are twodistinct pathways for trafficking of spore coat proteins during thedifferentiation of M. xanthus.
