Download MendeleyAlgK is a TPR-containing protein and the periplasmic component of a novel exopolysaccharide secretin.
Keiski, C.L., Harwich, M., Jain, S., Neculai, A.M., Yip, P., Robinson, H., Whitney, J.C., Riley, L., Burrows, L.L., Ohman, D.E., Howell, P.L.(2010) Structure 18: 265-273
- PubMed: 20159471
- DOI: https://doi.org/10.1016/j.str.2009.11.015
- Primary Citation of Related Structures:
3E4B - PubMed Abstract:
The opportunistic pathogen Pseudomonas aeruginosa causes chronic biofilm infections in cystic fibrosis patients. During colonization of the lung, P. aeruginosa converts to a mucoid phenotype characterized by overproduction of the exopolysaccharide alginate. Here we show that AlgK, a protein essential for production of high molecular weight alginate, is an outer membrane lipoprotein that contributes to the correct localization of the porin AlgE. Our 2.5 A structure shows AlgK is composed of 9.5 tetratricopeptide-like repeats, and three putative sites of protein-protein interaction have been identified. Bioinformatics analysis suggests that BcsA, PgaA, and PelB, involved in the production and export of cellulose, poly-beta-1,6-N-Acetyl-D-glucosamine, and Pel exopolysaccharide, respectively, share the same topology as AlgK/E. Together, our data suggest that AlgK plays a role in the assembly of the alginate biosynthetic complex and represents the periplasmic component of a new type of outer membrane secretin that differs from canonical bacterial capsular polysaccharide secretion systems.
Organizational Affiliation:
Molecular Structure and Function, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
