6AEQ

Crystal structure of the ssDNA-binding domain of DnaT from Salmonella enterica Serovar Typhimurium LT2

Summary for 6AEQ

• Entry DOI: 10.2210/pdb6aeq/pdb
• Descriptor: Primosomal protein 1 (2 entities in total)
• Functional Keywords: primosome, replication restart, dnat, dna binding, dna binding protein
• Biological source: Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)
• Total number of polymer chains: 2
• Total formula weight: 23292.06

Authors

Huang, Y.H.,Huang, C.Y. (deposition date: 2018-08-06, release date: 2019-03-20, Last modification date: 2024-10-16)

Primary citation

Chen, K.L.,Huang, Y.H.,Liao, J.F.,Lee, W.C.,Huang, C.Y.
Crystal structure of the C-terminal domain of the primosomal DnaT protein: Insights into a new oligomerization mechanism.
Biochem. Biophys. Res. Commun., 511:1-6, 2019

PubMed Abstract: DnaT is a replication restart primosomal protein required for re-initiating chromosomal DNA replication in bacteria. DnaT can be a monomer, dimer, trimer, tetramer, or pentamer. The oligomerization and disassembly of DnaT oligomers are critical in primosome assembly. Prior to this work, only the ssDNA-bound structure of the pentameric DnaT truncated protein (aa 84-153; DnaT84-153) was available. The mechanism by which DnaT oligomerizes as different states is unclear. In this paper, we report the crystal structure of the C-terminal domain of DnaT (aa 84-179; DnaTc) at 2.30 Å resolution (PDB entry 6AEQ). DnaTc forms a dimer both in the crystalline state and in solution. As compared with the ssDNA-bound structure of the pentameric DnaT84-153, their subunit-subunit interfaces significantly differ. The different oligomeric architecture suggests a strong conformational change possibly induced by ssDNA. Superposition analysis further indicated that the monomer of a DnaTc dimer shifted away by a distance of 7.5 Å and rotated by an angle of 170° for binding to ssDNA. Basing from these molecular evidence, we discussed and proposed a working model to explain how DnaTc oligomerizes through residue R146 mediation.

PubMed: 30755302
DOI: 10.1016/j.bbrc.2019.02.026

Experimental method

X-RAY DIFFRACTION (2.2518084706 Å)