PMID: 30220543

Authors:

Hajizadeh NR, Pieprzyk J, Skopintsev P, Flayhan A, Svergun DI, Low C

Title:

Probing the Architecture of a Multi-PDZ Domain Protein: Structure of PDZK1 in Solution.

Journal:

Structure. 2018 Aug 16. pii: S0969-2126(18)30262-4. doi:, 10.1016/j.str.2018.07.016.

Abstract:

The scaffolding protein PDZK1 has been associated with the regulation of membrane transporters. It contains four conserved PDZ domains, which typically recognize a 3-5-residue long motif at the C terminus of the binding partner. The atomic structures of the individual domains are available but their spatial arrangement in the full-length context influencing the binding properties remained elusive. Here we report a systematic study of full-length PDZK1 and deletion constructs using small-angle X-ray scattering, complemented with biochemical and functional studies on PDZK1 binding to known membrane protein partners. A hybrid modeling approach utilizing multiple scattering datasets yielded a well-defined, extended, asymmetric L-shaped domain organization of PDZK1 in contrast to a flexible "beads-on-string" model predicted by bioinformatics analysis. The linker regions of PDZK1 appear to play a central role in the arrangement of the four domains underlying the importance of studying scaffolding proteins in their full-length context.