| Type: | Domain | Name: | RlpA-like double-psi beta-barrel domain |
| Description: | Rare lipoprotein A (RlpA) contains a conserved region that has the double-psi beta-barrel (DPBB) fold [, ]. RlpA is a bacterial septal ring protein and a lytic transglycosylase that contributes to rod shape and daughter cell separation in Pseudomonas aeruginosa []. It has been shown to act as a prc mutant suppressor in Escherichia coli []. The DPBB fold is often an enzymatic domain. Proteins containing this domain are quite diverse and may have several different functions. Another example of this domain is found in the N terminus of pollen allergen.Beta barrels are commonly observed in protein structures. They are classified in terms of two integral parameters: the number of strands in the sheet, n, and the shear number, S, a measure of the stagger of the strands in the beta-sheet. These two parameters have been shown to determine the major geometrical features of beta-barrels. Six-stranded beta-barrels with a pseudo-twofold axis are found in several proteins. One involving parallel strands forming two psi structures is known as the double-psi barrel. The first psi structure consists of the loop connecting strands beta1 and beta2 (a 'psi loop') and the strand beta5, whereas the second psi structure consists of the loop connecting strands beta4 and beta5 and the strand beta2. All the psi structures in double-psi barrels have a unique handedness, in that beta1 (beta4), beta2 (beta5) and the loop following beta5 (beta2) form a right-handed helix. The unique handedness may be related to the fact that the twisting angle between the parallel pair of strands is always larger than that between the antiparallel pair []. | Short Name: | RlpA-like_DPBB |
