4IQJ

Structure of PolIIIalpha-Tauc-DNA complex suggests an atomic model of the replisome

Summary for 4IQJ

• Entry DOI: 10.2210/pdb4iqj/pdb
• Related: 2HPI 3E0D
• Descriptor: DNA (5'-D(P*CP*GP*AP*AP*AP*CP*GP*AP*CP*GP*GP*CP*CP*AP*GP*TP*GP*CP*CP*A)-3'), DNA (5'-D(*TP*TP*TP*TP*TP*TP*TP*GP*TP*GP*GP*CP*AP*CP*TP*GP*GP*CP*CP*GP*TP*CP*GP*TP*TP*TP*CP*G)-3'), DNA (5'-D(P*CP*GP*AP*AP*AP*CP*GP*AP*CP*GP*GP*CP*CP*AP*GP*TP*GP*CP*CP*AP*(DOC))-3'), ... (7 entities in total)
• Functional Keywords: polymerase, alpha subunit, tauc subunit, dna replication, dna-directed dna polymerase, nucleotidyltransferase, transferase-dna complex, transferase/dna
• Biological source: Thermus aquaticus; More
• Cellular location: Cytoplasm (By similarity): 4IQJ
• Total number of polymer chains: 16
• Total formula weight: 688792.08

Authors

Liu, B.,Lin, J.,Steitz, T. (deposition date: 2013-01-11, release date: 2013-03-13, Last modification date: 2023-09-20)

Primary citation

Liu, B.,Lin, J.,Steitz, T.A.
Structure of PolIIIalpha-Tauc-DNA complex suggests an atomic model of the replisome
Structure, 21:658-664, 2013

PubMed Abstract: The C-terminal domain (CTD) of the τ subunit of the clamp loader (τc) binds to both the DnaB helicase and the DNA polymerase III α subunit (PolIIIα), and determines their relative positions and orientations on the leading and lagging strands. Here, we present a 3.2 Å resolution structure of Thermus aquaticus PolIIIα in complex with τc and a DNA substrate. The structure reveals that the CTD of τc interacts with the CTD of PolIIIα through its C-terminal helix and the adjacent loop. Additionally, in this complex PolIIIα displays an open conformation that includes the reorientations of the oligonucleotide-binding fold and the thumb domain, which may be an indirect result of crystal packing due to the presence of the τc. Nevertheless, the position of the τc on PolIIIα allows us to suggest an approximate model for how the PolIIIα is oriented and positioned on the DnaB helicase.

PubMed: 23478062
DOI: 10.1016/j.str.2013.02.002

Experimental method

X-RAY DIFFRACTION (3.2 Å)