8OJJ

Cryo-EM structure of the DnaD-NTD tetramer

Summary for 8OJJ

• Entry DOI: 10.2210/pdb8ojj/pdb
• EMDB information: 16914
• Descriptor: DNA replication protein DnaD (1 entity in total)
• Functional Keywords: replication helicase loading, small cryo-em structure, dna binding protein
• Biological source: Bacillus subtilis subsp. subtilis str. 168
• Total number of polymer chains: 4
• Total formula weight: 110702.86

Authors

Winterhalter, C.,Pelliciari, S.,Cronin, N.,Costa, T.R.D.,Murray, H.,Ilangovan, A. (deposition date: 2023-03-24, release date: 2023-05-17, Last modification date: 2024-07-24)

Primary citation

Winterhalter, C.,Pelliciari, S.,Stevens, D.,Fenyk, S.,Marchand, E.,Cronin, N.B.,Soultanas, P.,Costa, T.R.D.,Ilangovan, A.,Murray, H.
The DNA replication initiation protein DnaD recognises a specific strand of the Bacillus subtilis chromosome origin.
Nucleic Acids Res., 51:4322-4340, 2023

PubMed Abstract: Genome replication is a fundamental biological activity shared by all organisms. Chromosomal replication proceeds bidirectionally from origins, requiring the loading of two helicases, one for each replisome. However, the molecular mechanisms underpinning helicase loading at bacterial chromosome origins (oriC) are unclear. Here we investigated the essential DNA replication initiation protein DnaD in the model organism Bacillus subtilis. A set of DnaD residues required for ssDNA binding was identified, and photo-crosslinking revealed that this ssDNA binding region interacts preferentially with one strand of oriC. Biochemical and genetic data support the model that DnaD recognizes a new single-stranded DNA (ssDNA) motif located in oriC, the DnaD Recognition Element (DRE). Considered with single particle cryo-electron microscopy (cryo-EM) imaging of DnaD, we propose that the location of the DRE within oriC orchestrates strand-specific recruitment of helicase during DNA replication initiation. These findings significantly advance our mechanistic understanding of bidirectional replication from a bacterial chromosome origin.

PubMed: 37093985
DOI: 10.1093/nar/gkad277

Experimental method

ELECTRON MICROSCOPY (5.47 Å)