5WTN

Crystal Structure Analysis of primosome protein DnaB (resiues 1-300) from Geobacillus stearothermophilus

Summary for 5WTN

• Entry DOI: 10.2210/pdb5wtn/pdb
• Descriptor: Replication initiation and membrane attachment protein (2 entities in total)
• Functional Keywords: primosome, dnab, dna replication, replication
• Biological source: Geobacillus stearothermophilus 10
• Total number of polymer chains: 4
• Total formula weight: 138215.45

Authors

Li, Y.C.,Hsiao, C.D. (deposition date: 2016-12-13, release date: 2017-08-23, Last modification date: 2024-03-20)

Primary citation

Li, Y.C.,Naveen, V.,Lin, M.G.,Hsiao, C.D.
Structural analyses of the bacterial primosomal protein DnaB reveal that it is a tetramer and forms a complex with a primosomal re-initiation protein
J. Biol. Chem., 292:15744-15757, 2017

PubMed Abstract: The DnaB primosomal protein from Gram-positive bacteria plays a key role in DNA replication and restart as a loader protein for the recruitment of replisome cascade proteins. Previous investigations have established that DnaB is composed of an N-terminal domain, a middle domain, and a C-terminal domain. However, structural evidence for how DnaB functions at the atomic level is lacking. Here, we report the crystal structure of DnaB, encompassing the N-terminal and middle domains (residues 1-300), from (DnaB) at 2.8 Å resolution. Our structure revealed that DnaB forms a tetramer with two basket-like architectures, a finding consistent with those from solution studies using analytical ultracentrifugation. Furthermore, our results from both GST pulldown assays and analytical ultracentrifugation show that DnaB is sufficient to form a complex with PriA, the primosomal reinitiation protein. Moreover, with the aid of small angle X-ray scattering experiments, we also determined the structural envelope of full-length DnaB (DnaB) in solution. These small angle X-ray scattering studies indicated that DnaB has an elongated conformation and that the protruding density envelopes originating from DnaB could completely accommodate the DnaB C-terminal domain (residues 301-461). Taken together with biochemical assays, our results suggest that DnaB uses different domains to distinguish the PriA interaction and single-stranded DNA binding. These findings can further extend our understanding of primosomal assembly in replication restart.

PubMed: 28808061
DOI: 10.1074/jbc.M117.792002

Experimental method

X-RAY DIFFRACTION (2.8 Å)