title: The First Residue of the PWWP Motif Modulates HATH Domain Binding, Stability, and Protein-Protein Interaction.
abstract: Hepatoma-derived growth factor (hHDGF) and HDGF-related proteins (HRPs) contain conserved N-terminal HATH domains with a characteristic structural motif, namely the PWWP motif. The HATH domain has attracted attention because of its ability to bind with heparin/heparan sulfate, DNA, and methylated histone peptide. Depending on the sequence of the PWWP motif, HRP HATHs are classified into P-type (Pro-His-Trp-Pro) and A-type (Ala-His-Trp-Pro) forms. A-type HATH is highly unstable and tends to precipitate in solution. We replaced the Pro residue in P-type HATHHDGF with Ala and evaluated the influence on structure, dynamics, and ligand binding. Nuclear magnetic resonance (NMR) hydrogen/deuterium exchange and circular dichroism (CD) measurements revealed reduced stability. Analysis of NMR backbone (15)N relaxations (R1, R2, and nuclear Overhauser effect) revealed additional backbone dynamics in the interface between the β-barrel and the C-terminal helix bundle. The β1-β2 loop, where the AHWP sequence is located, has great structural flexibility, which aids HATH-HATH interaction through the loop. A-type HATH, therefore, shows a stronger tendency to aggregate when binding with heparin and DNA oligomers. This study defines the role of the first residue of the PWWP motif in modulating HATH domain stability and oligomer formation in binding.
authors.forename: Yi-Lin
authors.initials: YL
authors.lastname: Hung
authors.forename: Hsia-Ju
authors.initials: HJ
authors.lastname: Lee
authors.forename: Ingjye
authors.initials: I
authors.lastname: Jiang
authors.forename: Shang-Chi
authors.initials: SC
authors.lastname: Lin
authors.affiliation: §Institute of Bioinformatics and Structural Biology, National Chiao Tung University, Hsinchu, Taiwan.
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Lo
authors.affiliation: ∥Graduate Institute of Natural Products and Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Yi-Jan
authors.initials: YJ
authors.lastname: Lin
authors.forename: Shih-Che
authors.initials: SC
authors.lastname: Sue
mesh_terms: D000595:Amino Acid Sequence; D004247:DNA / Q000378:metabolism; D006493:Heparin / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D055550:Protein Stability; D016415:Sequence Alignment
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; C051610:hepatoma-derived growth factor; D006493:Heparin; D004247:DNA