The clamp-loader-helicase interaction in Bacillus. Atomic force microscopy reveals the structural organisation of the DnaB-tau complex in Bacillus.
The clamp-loader-helicase interaction is an important feature of the replisome. Although significant biochemical and structural work has been carried out on the clamp-loader-clamp-DNA polymerase alpha interactions in Escherichia coli, the clamp-loader-helicase interaction is poorly understood by comparison. The tau subunit of the clamp-loader mediates the interaction with DnaB. We have recently characterised this interaction in the Bacillus system and established a tau(5)-DnaB(6) stoichiometry. Here, we have obtained atomic force microscopy images of the tau-DnaB complex that reveal the first structural insight into its architecture. We show that despite the reported absence of the shorter gamma version in Bacillus, tau has a domain organisation similar to its E.coli counterpart and possesses an equivalent C-terminal domain that interacts with DnaB. The interaction interface of DnaB is also localised in its C-terminal domain. The combined data contribute towards our understanding of the bacterial replisome.
Haroniti
Anna
A
School of Chemistry, University of Nottingham, University Park, NG7 2RD, Nottingham, UK.
Anderson
Christopher
C
Doddridge
Zara
Z
Gardiner
Laurence
L
Roberts
Clive J
CJ
Allen
Stephanie
S
Soultanas
Panos
P
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins; D001483:Base Sequence; D004265:DNA Helicases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure*; D004261:DNA Replication; D053488:DnaB Helicases; D004578:Electron Spin Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism*
D001426:Bacterial Proteins; D021122:Protein Subunits; D000251:Adenosine Triphosphatases; D004265:DNA Helicases; D053488:DnaB Helicases