4A1F

Crystal structure of C-terminal domain of Helicobacter pylori DnaB Helicase

Summary for 4A1F

• Entry DOI: 10.2210/pdb4a1f/pdb
• Descriptor: REPLICATIVE DNA HELICASE, CITRATE ANION (3 entities in total)
• Functional Keywords: hydrolase, dna replication, atpase
• Biological source: HELICOBACTER PYLORI
• Total number of polymer chains: 2
• Total formula weight: 77953.18

Authors

Stelter, M.,Kapp, U.,Timmins, J.,Terradot, L. (deposition date: 2011-09-14, release date: 2012-03-21, Last modification date: 2024-05-08)

Primary citation

Stelter, M.,Gutsche, I.,Kapp, U.,Bazin, A.,Bajic, G.,Goret, G.,Jamin, M.,Timmins, J.,Terradot, L.
Architecture of a Dodecameric Bacterial Replicative Helicase.
Structure, 20:554-, 2012

PubMed Abstract: Hexameric DnaB helicases are often loaded at DNA replication forks by interacting with the initiator protein DnaA and/or a helicase loader (DnaC in Escherichia coli). These loaders are not universally required, and DnaB from Helicobacter pylori was found to bypass DnaC when expressed in E. coli cells. The crystal structure of Helicobacter pylori DnaB C-terminal domain (HpDnaB-CTD) reveals a large two-helix insertion (named HPI) in the ATPase domain that protrudes away from the RecA fold. Biophysical characterization and electron microscopy (EM) analysis of the full-length protein show that HpDnaB forms head-to-head double hexamers remarkably similar to helicases found in some eukaryotes, archaea, and viruses. The docking of the HpDnaB-CTD structure into EM reconstruction of HpDnaB provides a model that shows how hexamerization of the CTD is facilitated by HPI-HPI interactions. The HpDnaB double-hexamer architecture supports an alternative strategy to load bacterial helicases onto forks in the absence of helicase loaders.

PubMed: 22405014
DOI: 10.1016/J.STR.2012.01.020

Experimental method

X-RAY DIFFRACTION (2.5 Å)