7DUV

Structure of Sulfolobus solfataricus SegB protein

Summary for 7DUV

• Entry DOI: 10.2210/pdb7duv/pdb
• Descriptor: SegB, SULFATE ION (3 entities in total)
• Functional Keywords: dna binding protein
• Biological source: Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2)
• Total number of polymer chains: 3
• Total formula weight: 41639.98

Authors

Yen, C.Y.,Lin, M.G.,Sun, Y.J.,Hsiao, C.D. (deposition date: 2021-01-11, release date: 2021-12-22, Last modification date: 2024-05-29)

Primary citation

Yen, C.Y.,Lin, M.G.,Chen, B.W.,Ng, I.W.,Read, N.,Kabli, A.F.,Wu, C.T.,Shen, Y.Y.,Chen, C.H.,Barilla, D.,Sun, Y.J.,Hsiao, C.D.
Chromosome segregation in Archaea: SegA- and SegB-DNA complex structures provide insights into segrosome assembly.
Nucleic Acids Res., 49:13150-13164, 2021

PubMed Abstract: Genome segregation is a vital process in all organisms. Chromosome partitioning remains obscure in Archaea, the third domain of life. Here, we investigated the SegAB system from Sulfolobus solfataricus. SegA is a ParA Walker-type ATPase and SegB is a site-specific DNA-binding protein. We determined the structures of both proteins and those of SegA-DNA and SegB-DNA complexes. The SegA structure revealed an atypical, novel non-sandwich dimer that binds DNA either in the presence or in the absence of ATP. The SegB structure disclosed a ribbon-helix-helix motif through which the protein binds DNA site specifically. The association of multiple interacting SegB dimers with the DNA results in a higher order chromatin-like structure. The unstructured SegB N-terminus plays an essential catalytic role in stimulating SegA ATPase activity and an architectural regulatory role in segrosome (SegA-SegB-DNA) formation. Electron microscopy results also provide a compact ring-like segrosome structure related to chromosome organization. These findings contribute a novel mechanistic perspective on archaeal chromosome segregation.

PubMed: 34850144
DOI: 10.1093/nar/gkab1155

Experimental method

X-RAY DIFFRACTION (3.2 Å)