8XAQ

The thermostable and acid-tolerant DNA-binding protein

8XAQ の概要

• エントリーDOI: 10.2210/pdb8xaq/pdb
• 関連するPDBエントリー: 8XAO 8XAP
• 分子名称: DNA/RNA-binding protein Alba (2 entities in total)
• 機能のキーワード: thermostable, acid-tolerant dna-binding protein, dna binding protein
• 由来する生物種: Sulfolobus acidocaldarius DSM 639
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 20886.41

構造登録者

Chen, C.Y.,Huang, C.H. (登録日: 2023-12-05, 公開日: 2024-12-11, 最終更新日: 2025-06-25)

主引用文献

Tang, S.,Huang, C.H.,Ko, T.P.,Lin, K.F.,Chang, Y.C.,Lin, P.Y.,Sun, L.,Chen, C.Y.
Dual dimeric interactions in the nucleic acid-binding protein Sac10b lead to multiple bridging of double-stranded DNA.
Heliyon, 10:e31630-e31630, 2024

PubMed Abstract: Nucleoid-associated proteins play a crucial role in the compaction and regulation of genetic material across organisms. The Sac10b family, also known as Alba, comprises widely distributed and highly conserved nucleoid-associated proteins found in archaea. Sac10b is identified as the first 10 kDa DNA-binding protein in the thermoacidophile . Here, we present the crystal structures of two homologous proteins, Sac10b1 and Sac10b2, as well as the Sac10b1 mutant F59A, determined at a resolution of 1.4-2.0 Å. Electron microscopic images reveal the DNA-bridging capabilities of both Sac10b1 and Sac10b2, albeit to varying extents. Analyses of crystal packing and electron microscopic results suggest that Sac10b1 facilitates cooperative DNA binding, forming extensive bridged filaments via the conserved R58 and F59 residues at the dimer-dimer interface. Substitutions at R58 or F59 of Sac10b1 attenuate end-to-end association, resulting in non-cooperative DNA binding, and formation of small, bridged DNA segments in a way similar to Sac10b2. Analytical ultracentrifuge and circular dichroism confirm the presence of thermostable, acid-tolerant dimers in both Sac10b1 and Sac10b2. These findings attest to the functional role of Sac10b in organizing and stabilizing chromosomal DNA through distinct bridging interactions, particularly under extreme growth conditions.

PubMed: 38867953
DOI: 10.1016/j.heliyon.2024.e31630

実験手法

X-RAY DIFFRACTION (1.4 Å)