3GXV

Three-dimensional structure of N-terminal domain of DnaB Helicase from Helicobacter pylori and its interactions with primase

Summary for 3GXV

• Entry DOI: 10.2210/pdb3gxv/pdb
• Descriptor: Replicative DNA helicase, ... (4 entities in total)
• Functional Keywords: hexameric helicase, helicobacter pylori, primase, replication, atp-binding, autocatalytic cleavage, dna replication, dna-binding hydrolase, nucleotide-binding, primosome, dna-binding, helicase, hydrolase, hydrolase-replication complex, hydrolase/replication
• Biological source: Helicobacter pylori; More
• Total number of polymer chains: 4
• Total formula weight: 34049.10

Authors

Kashav, T.,Nitharwal, R.,Syed, A.A.,Gabdoulkhakov, A.,Saenger, W.,Dhar, K.S.,Gourinath, S. (deposition date: 2009-04-03, release date: 2010-01-26, Last modification date: 2023-11-01)

Primary citation

Kashav, T.,Nitharwal, R.,Abdulrehman, S.A.,Gabdoulkhakov, A.,Saenger, W.,Dhar, S.K.,Gourinath, S.
Three-dimensional structure of N-terminal domain of DnaB helicase and helicase-primase interactions in Helicobacter pylori
Plos One, 4:e7515-e7515, 2009

PubMed Abstract: Replication initiation is a crucial step in genome duplication and homohexameric DnaB helicase plays a central role in the replication initiation process by unwinding the duplex DNA and interacting with several other proteins during the process of replication. N-terminal domain of DnaB is critical for helicase activity and for DnaG primase interactions. We present here the crystal structure of the N-terminal domain (NTD) of H. pylori DnaB (HpDnaB) helicase at 2.2 A resolution and compare the structural differences among helicases and correlate with the functional differences. The structural details of NTD suggest that the linker region between NTD and C-terminal helicase domain plays a vital role in accurate assembly of NTD dimers. The sequence analysis of the linker regions from several helicases reveals that they should form four helix bundles. We also report the characterization of H. pylori DnaG primase and study the helicase-primase interactions, where HpDnaG primase stimulates DNA unwinding activity of HpDnaB suggesting presence of helicase-primase cohort at the replication fork. The protein-protein interaction study of C-terminal domain of primase and different deletion constructs of helicase suggests that linker is essential for proper conformation of NTD to interact strongly with HpDnaG. The surface charge distribution on the primase binding surface of NTDs of various helicases suggests that DnaB-DnaG interaction and stability of the complex is most probably charge dependent. Structure of the linker and helicase-primase interactions indicate that HpDnaB differs greatly from E.coli DnaB despite both belong to gram negative bacteria.

PubMed: 19841750
DOI: 10.1371/journal.pone.0007515

Experimental method

X-RAY DIFFRACTION (2.2 Å)