Structural basis for controlling the dimerization and stability of the WW domains of an atypical subfamily.

Abstract

The second WW domain in mammalian Salvador protein (SAV1 WW2) is quite atypical, as it forms a beta-clam-like homodimer. The second WW domain in human MAGI1 (membrane associated guanylate kinase, WW and PDZ domain containing 1) (MAGI1 WW2) shares high sequence similarity with SAV1 WW2, suggesting comparable dimerization. However, an analytical ultracentrifugation study revealed that MAGI1 WW2 (Leu355-Pro390) chiefly exists as a monomer at low protein concentrations, with an association constant of 1.3 x 10(2) M(-1). We determined its solution structure, and a structural comparison with the dimeric SAV1 WW2 suggested that an Asp residue is crucial for the inhibition of the dimerization. The substitution of this acidic residue with Ser resulted in the dimerization of MAGI1 WW2. The spin-relaxation data suggested that the MAGI1 WW2 undergoes a dynamic process of transient dimerization that is limited by the charge repulsion. Additionally, we characterized a longer construct of this WW domain with a C-terminal extension (Leu355-Glu401), as the formation of an extra alpha-helix was predicted. An NMR structural determination confirmed the formation of an alpha-helix in the extended C-terminal region, which appears to be independent from the dimerization regulation. A thermal denaturation study revealed that the dimerized MAGI1 WW2 with the Asp-to-Ser mutation gained apparent stability in a protein concentration-dependent manner. A structural comparison between the two constructs with different lengths suggested that the formation of the C-terminal alpha-helix stabilized the global fold by facilitating contacts between the N-terminal linker region and the main body of the WW domain. Study holds ProTherm entries: 24896, 24897, 24898, 24899, 24900, 24901, 24902, 24903 Extra Details: Region 355-390 WW domain; dimerization; stability; dynamics; ultracentrifuge; NMR

Submission Details

ID: TzxedoMZ3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:55 p.m.

Version: 1

Publication Details
Ohnishi S;Tochio N;Tomizawa T;Akasaka R;Harada T;Seki E;Sato M;Watanabe S;Fujikura Y;Koshiba S;Terada T;Shirouzu M;Tanaka A;Kigawa T;Yokoyama S,Protein Sci. (2008) Structural basis for controlling the dimerization and stability of the WW domains of an atypical subfamily. PMID:18562638
Additional Information

Study Summary

Number of data points 12
Proteins Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 1 ; Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 1
Unique complexes 2
Assays/Quantities/Protocols Experimental Assay: dG prot_conc:5 microM ; Experimental Assay: dG prot_conc:55 microM ; Experimental Assay: dG prot_conc:35-85 microM ; Experimental Assay: Tm prot_conc:5 microM ; Experimental Assay: dHvH prot_conc:5 microM ; Experimental Assay: Tm prot_conc:55 microM ; Experimental Assay: dHvH prot_conc:55 microM ; Experimental Assay: Tm prot_conc:35-85 microM ; Experimental Assay: dHvH prot_conc:35-85 microM
Libraries Mutations for sequence GSSGSSGLDSELELPAGWEKIEDPVYGIYYVDHINRKTQYENPSGPSSG

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 1 Q96QZ7 MAGI1_HUMAN
97.2 Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 1 Q6RHR9 MAGI1_MOUSE
97.2 Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 1 Q4L1J4 MAGI1_RAT