6TV5

NMR structure of N-terminal domain from A. argentata tubuliform spidroin (TuSp) at pH 5.5

6TV5 の概要

• エントリーDOI: 10.2210/pdb6tv5/pdb
• NMR情報: BMRB: 34473
• 分子名称: Tubuliform spidroin 1 (1 entity in total)
• 機能のキーワード: spidroin, n-terminal domain, spidersilk, structural protein
• 由来する生物種: Argiope argentata
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 28110.89

構造登録者

Fridmanis, J.,Jaudzems, K. (登録日: 2020-01-09, 公開日: 2021-01-27, 最終更新日: 2023-06-14)

主引用文献

Sede, M.,Fridmanis, J.,Otikovs, M.,Johansson, J.,Rising, A.,Kronqvist, N.,Jaudzems, K.
Solution Structure of Tubuliform Spidroin N-Terminal Domain and Implications for pH Dependent Dimerization.
Front Mol Biosci, 9:936887-936887, 2022

PubMed Abstract: The spidroin N-terminal domain (NT) is responsible for high solubility and pH-dependent assembly of spider silk proteins during storage and fiber formation, respectively. It forms a monomeric five-helix bundle at neutral pH and dimerizes at lowered pH, thereby firmly interconnecting the spidroins. Mechanistic studies with the NTs from major ampullate, minor ampullate, and flagelliform spidroins (MaSp, MiSp, and FlSp) have shown that the pH dependency is conserved between different silk types, although the residues that mediate this process can differ. Here we study the tubuliform spidroin (TuSp) NT from , which lacks several well conserved residues involved in the dimerization of other NTs. We solve its structure at low pH revealing an antiparallel dimer of two five-α-helix bundles, which contrasts with a previously determined TuSp NT monomer structure. Further, we study a set of mutants and find that the residues participating in the protonation events during dimerization are different from MaSp and MiSp NT. Charge reversal of one of these residues (R117 in TuSp) results in significantly altered electrostatic interactions between monomer subunits. Altogether, the structure and mutant studies suggest that TuSp NT monomers assemble by elimination of intramolecular repulsive charge interactions, which could lead to slight tilting of α-helices.

PubMed: 35775078
DOI: 10.3389/fmolb.2022.936887

実験手法

SOLUTION NMR