Download MendeleyCrystal structure of the C-terminal domain of the primosomal DnaT protein: Insights into a new oligomerization mechanism.
Chen, K.L., Huang, Y.H., Liao, J.F., Lee, W.C., Huang, C.Y.(2019) Biochem Biophys Res Commun 511: 1-6
- PubMed: 30755302
- DOI: https://doi.org/10.1016/j.bbrc.2019.02.026
- Primary Citation of Related Structures:
6AEQ - 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.
Organizational Affiliation:
School of Biomedical Sciences, Chung Shan Medical University, No.110, Sec.1, Chien-Kuo N. Rd., Taichung City, Taiwan.
