6R9D

Crystal structure of an asymmetric dimer of the N-terminal domain of Euprosthenops australis Major Ampullate Spidroin 1 (dragline silk)

6R9D の概要

• エントリーDOI: 10.2210/pdb6r9d/pdb
• 分子名称: Major ampullate spidroin 1, SULFATE ION (3 entities in total)
• 機能のキーワード: spider silk spidroin n-terminal domain ph relay assembly, protein fibril
• 由来する生物種: Euprosthenops australis
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 85018.18

構造登録者

Knight, S.D.,Jiang, W.,Askarieh, G. (登録日: 2019-04-03, 公開日: 2019-07-17, 最終更新日: 2024-01-24)

主引用文献

Jiang, W.,Askarieh, G.,Shkumatov, A.,Hedhammar, M.,Knight, S.D.
Structure of the N-terminal domain of Euprosthenops australis dragline silk suggests that conversion of spidroin dope to spider silk involves a conserved asymmetric dimer intermediate.
Acta Crystallogr D Struct Biol, 75:618-627, 2019

PubMed Abstract: Spider silk is a biomaterial with exceptional mechanical toughness, and there is great interest in developing biomimetic methods to produce engineered spider silk-based materials. However, the mechanisms that regulate the conversion of spider silk proteins (spidroins) from highly soluble dope into silk are not completely understood. The N-terminal domain (NT) of Euprosthenops australis dragline silk protein undergoes conformational and quaternary-structure changes from a monomer at a pH above 7 to a homodimer at lower pH values. Conversion from the monomer to the dimer requires the protonation of three conserved glutamic acid residues, resulting in a low-pH `locked' dimer stabilized by symmetric electrostatic interactions at the poles of the dimer. The detailed molecular events during this transition are still unresolved. Here, a 2.1 Å resolution crystal structure of an NT T61A mutant in an alternative, asymmetric, dimer form in which the electrostatic interactions at one of the poles are dramatically different from those in symmetrical dimers is presented. A similar asymmetric dimer structure from dragline silk of Nephila clavipes has previously been described. It is suggested that asymmetric dimers represent a conserved intermediate state in spider silk formation, and a revised `lock-and-trigger' mechanism for spider silk formation is presented.

PubMed: 31282471
DOI: 10.1107/S2059798319007253

実験手法

X-RAY DIFFRACTION (2.1 Å)