- EMDB-37713: Small-heat shock protein from Methanocaldococcus jannaschii, Hsp16.5 -
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基本情報
登録情報
データベース: EMDB / ID: EMD-37713
タイトル
Small-heat shock protein from Methanocaldococcus jannaschii, Hsp16.5
マップデータ
試料
複合体: Small-heat shock protein from Methanocaldococcus jannaschii, Hsp16.5
タンパク質・ペプチド: Small heat shock protein HSP16.5
キーワード
Hsp16.5 / molecular chaperone / oligomeric protein / small heat-shock protein / stress response / CHAPERONE
機能・相同性
機能・相同性情報
protein complex oligomerization / response to salt stress / protein folding chaperone / response to hydrogen peroxide / unfolded protein binding / protein folding / response to heat / protein stabilization / protein-containing complex / identical protein binding / cytoplasm 類似検索 - 分子機能
Hsp20/alpha crystallin family / Small heat shock protein (sHSP) domain profile. / Alpha crystallin/Hsp20 domain / HSP20-like chaperone 類似検索 - ドメイン・相同性
ジャーナル: Int J Biol Macromol / 年: 2024 タイトル: Cryo-EM structure of a 16.5-kDa small heat-shock protein from Methanocaldococcus jannaschii. 著者: Joohyun Lee / Bumhan Ryu / Truc Kim / Kyeong Kyu Kim / 要旨: The small heat-shock protein (sHSP) from the archaea Methanocaldococcus jannaschii, MjsHSP16.5, functions as a broad substrate ATP-independent holding chaperone protecting misfolded proteins from ...The small heat-shock protein (sHSP) from the archaea Methanocaldococcus jannaschii, MjsHSP16.5, functions as a broad substrate ATP-independent holding chaperone protecting misfolded proteins from aggregation under stress conditions. This protein is the first sHSP characterized by X-ray crystallography, thereby contributing significantly to our understanding of sHSPs. However, despite numerous studies assessing its functions and structures, the precise arrangement of the N-terminal domains (NTDs) within this sHSP cage remains elusive. Here we present the cryo-electron microscopy (cryo-EM) structure of MjsHSP16.5 at 2.49-Å resolution. The subunits of MjsHSP16.5 in the cryo-EM structure exhibit lesser compaction compared to their counterparts in the crystal structure. This structural feature holds particular significance in relation to the biophysical properties of MjsHSP16.5, suggesting a close resemblance to this sHSP native state. Additionally, our cryo-EM structure unveils the density of residues 24-33 within the NTD of MjsHSP16.5, a feature that typically remains invisible in the majority of its crystal structures. Notably, these residues show a propensity to adopt a β-strand conformation and engage in antiparallel interactions with strand β1, both intra- and inter-subunit modes. These structural insights are corroborated by structural predictions, disulfide bond cross-linking studies of Cys-substitution mutants, and protein disaggregation assays. A comprehensive understanding of the structural features of MjsHSP16.5 expectedly holds the potential to inspire a wide range of interdisciplinary applications, owing to the renowned versatility of this sHSP as a nanoscale protein platform.