6XRY

Intrinsically disordered bacterial polar organizing protein Z, PopZ, interacts with protein binding partners through an N-terminal Molecular Recognition Feature

Summary for 6XRY

• Entry DOI: 10.2210/pdb6xry/pdb
• NMR Information: BMRB: 30773
• Descriptor: Polar organizing protein Z (1 entity in total)
• Functional Keywords: molecular recognition feature, morf, hub protein, protein binding
• Biological source: Caulobacter vibrioides (strain ATCC 19089 / CB15)
• Total number of polymer chains: 1
• Total formula weight: 14988.29

Authors

Nordyke, C.T.,Ahmed, Y.M.,Puterbaugh, R.Z.,Bowman, G.R.,Varga, K. (deposition date: 2020-07-14, release date: 2020-11-04, Last modification date: 2024-05-15)

Primary citation

Nordyke, C.T.,Ahmed, Y.M.,Puterbaugh, R.Z.,Bowman, G.R.,Varga, K.
Intrinsically Disordered Bacterial Polar Organizing Protein Z, PopZ, Interacts with Protein Binding Partners Through an N-terminal Molecular Recognition Feature.
J.Mol.Biol., 432:6092-6107, 2020

PubMed Abstract: The polar organizing protein Z (PopZ) is necessary for the formation of three-dimensional microdomains at the cell poles in Caulobacter crescentus, where it functions as a hub protein that recruits multiple regulatory proteins from the cytoplasm. Although a large portion of the protein is predicted to be natively unstructured, in reconstituted systems PopZ can self-assemble into a macromolecular scaffold that directly binds to at least ten different proteins. Here we report the solution NMR structure of PopZ, a truncated form of PopZ that does not self-assemble but retains the ability to interact with heterologous proteins. We show that the unbound form of PopZ is unstructured in solution, with the exception of a small amphipathic α-helix in residues M10-I17, which is included within a highly conserved region near the N-terminal. In applying NMR techniques to map the interactions between PopZ and one of its binding partners, RcdA, we find evidence that the α-helix and adjoining amino acids extending to position E23 serve as the core of the binding motif. Consistent with this, a point mutation at position I17 severely compromises binding. Our results show that a partially structured Molecular Recognition Feature (MoRF) within an intrinsically disordered domain of PopZ contributes to the assembly of polar microdomains, revealing a structural basis for complex network assembly in Alphaproteobacteria that is analogous to those formed by intrinsically disordered hub proteins in other kingdoms.

PubMed: 33058876
DOI: 10.1016/j.jmb.2020.09.020

Experimental method

SOLUTION NMR