| Primary Identifier | IPR034746 | Type | Domain |
| Short Name | POTRA |
| description | The polypeptide-transport-associated (POTRA) domain is a module found inmembers of the FtsQ/DivIB, ShlB, CGI51 (with one repeat), Toc75, YTFM (withthree repeats) and D15 (with five repeats) protein families. The POTRA domainsare hypothesized to mediate protein-protein interactions, nucleate beta-strands formation in nascent outer membrane proteins (OMPs) and havechaperone-like activity [, , , , ].The POTRA domain fold comprises a three-stranded β-sheet overlaid with apair of antiparallel helices. The order of secondary-structure elements isbeta-α-α-β-β; the first and second beta strands form the twoedges of the sheet, with the beta3 strand sandwiched between them. The conserved residues that define the POTRA domains areprimarily in the hydrophobic core or loop regions, suggesting that they areimportant for the structural integrity of POTRA domain [, , , ].Some proteins known to contain a POTRA domain are listed below:Escherichia coli outer membrane protein assembly factor BamA, involved inassembly and insertion of β-barrel proteins into the outer membrane.Escherichia coli cell division protein FtsQ.Bacillus subtilis cell division protein DivIB.Serratia marcescens hemolysin transporter protein ShlB, a virulence-factortransporter that is present in the outer membrane.Arabidopsis thaliana chloroplastic protein TOC75, mediates the insertion ofproteins targeted to the outer membrane of chloroplasts.Human sorting and assembly machinery component 50 (SAM50), plays a crucialrole in the maintenance of the structure of mitochondrial cristae and theproper assembly of the mitochondrial respiratory chain complexes. |
