4RT0

Structure of the Alg44 PilZ domain from Pseudomonas aeruginosa PAO1 in complex with c-di-GMP

Summary for 4RT0

• Entry DOI: 10.2210/pdb4rt0/pdb
• Related: 4RT1
• Descriptor: Alginate biosynthesis protein Alg44, 9,9'-[(2R,3R,3aS,5S,7aR,9R,10R,10aS,12S,14aR)-3,5,10,12-tetrahydroxy-5,12-dioxidooctahydro-2H,7H-difuro[3,2-d:3',2'-j][1,3,7,9,2,8]tetraoxadiphosphacyclododecine-2,9-diyl]bis(2-amino-1,9-dihydro-6H-purin-6-one), 1,2-ETHANEDIOL, ... (4 entities in total)
• Functional Keywords: pilz domain, c-di-gmp receptor, protein binding
• Biological source: Pseudomonas aeruginosa
• Cellular location: Periplasm : Q9HY69
• Total number of polymer chains: 3
• Total formula weight: 41724.83

Authors

Whitfield, G.B.,Whitney, J.C. (deposition date: 2014-11-12, release date: 2015-04-08, Last modification date: 2024-11-06)

Primary citation

Whitney, J.C.,Whitfield, G.B.,Marmont, L.S.,Yip, P.,Neculai, A.M.,Lobsanov, Y.D.,Robinson, H.,Ohman, D.E.,Howell, P.L.
Dimeric c-di-GMP Is Required for Post-translational Regulation of Alginate Production in Pseudomonas aeruginosa.
J.Biol.Chem., 290:12451-12462, 2015

PubMed Abstract: Pseudomonas aeruginosa is an opportunistic human pathogen that secretes the exopolysaccharide alginate during infection of the respiratory tract of individuals afflicted with cystic fibrosis and chronic obstructive pulmonary disease. Among the proteins required for alginate production, Alg44 has been identified as an inner membrane protein whose bis-(3',5')-cyclic dimeric guanosine monophosphate (c-di-GMP) binding activity post-translationally regulates alginate secretion. In this study, we report the 1.8 Å crystal structure of the cytoplasmic region of Alg44 in complex with dimeric self-intercalated c-di-GMP and characterize its dinucleotide-binding site using mutational analysis. The structure shows that the c-di-GMP binding region of Alg44 adopts a PilZ domain fold with a dimerization mode not previously observed for this family of proteins. Calorimetric binding analysis of residues in the c-di-GMP binding site demonstrate that mutation of Arg-17 and Arg-95 alters the binding stoichiometry between c-di-GMP and Alg44 from 2:1 to 1:1. Introduction of these mutant alleles on the P. aeruginosa chromosome show that the residues required for binding of dimeric c-di-GMP in vitro are also required for efficient alginate production in vivo. These results suggest that the dimeric form of c-di-GMP represents the biologically active signaling molecule needed for the secretion of an important virulence factor produced by P. aeruginosa.

PubMed: 25817996
DOI: 10.1074/jbc.M115.645051

Experimental method

X-RAY DIFFRACTION (1.8 Å)