Protein Family Models

Chaperone protein SycN is part of the type III secretion system and functions as a specific chaperone for YopN which may facilitate the secretion and the subsequent translocation of YopN [1]. Paper describing PDB structure 1xkp. [1]. 15701523. Three-dimensional structure of a macromolecular assembly that regulates type III secretion in Yersinia pestis. Schubot FD, Jackson MW, Penrose KJ, Cherry S, Tropea JE, Plano GV, Waugh DS;. J Mol Biol. 2005;346:1147-1161. (from Pfam)

Date:

2024-10-16

This family consists of a number of bacterial sequences which are highly similar to the Tir chaperone protein in E. Coli. In many Gram-negative bacteria, a key indicator of pathogenic potential is the possession of a specialised type III secretion system, which is utilised to deliver virulence effector proteins directly into the host cell cytosol. Many of the proteins secreted from such systems require small cytosolic chaperones to maintain the secreted substrates in a secretion-competent state. CesT serves a chaperone function for the enteropathogenic Escherichia coli (EPEC) translocated intimin receptor (Tir) protein, which confers upon EPEC the ability to alter host cell morphology following intimate bacterial attachment [1]. This family also contains several DspF and related sequences from several plant pathogenic bacteria. The "disease-specific" (dsp) region next to the hrp gene cluster of Erwinia amylovora is required for pathogenicity but not for elicitation of the hypersensitive reaction. DspF and AvrF are small (16 kDa and 14 kDa) and acidic with predicted amphipathic alpha helices in their C termini; they resemble chaperones for virulence factors secreted by type III secretion systems of animal pathogens [2]. [1]. 11849537. Functional analysis of the enteropathogenic Escherichia coli type III secretion system chaperone CesT identifies domains that mediate substrate interactions. Delahay RM, Shaw RK, Elliott SJ, Kaper JB, Knutton S, Frankel G;. Mol Microbiol 2002;43:61-73. [2]. 9448330. Homology and functional similarity of an hrp-linked pathogenicity locus, dspEF, of Erwinia amylovora and the avirulence l. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

Members of this protein family are part of the machinery of bacterial type III secretion in a number of bacteria that target animal cells. In the well-studied system from Yersinia, a complex of this protein (SycN) and YscB (PF07329) acts as a chaperone for the export of YopN (PMID:10094626). YopN then acts to control effector protein secretion, in response to calcium levels, so that secretion occurs only after contact with the targeted eukaryotic cell.

Gene:

sycN

Date:

2024-05-30

type III secretion chaperone SycN acts as a specific chaperone for YopN and may facilitate its secretion and subsequent translocation

Date:

2018-07-30