Literature summary for 3.6.4.B8 extracted from

Tondnevis, F.; Gillilan, R.E.; Bloom, L.B.; McKenna, R.
Solution study of the Escherichia coli DNA polymerase III clamp loader reveals the location of the dynamic psichi heterodimer (2015), Struct. Dyn., 2, 54701 .

Search for more literature for 3.6.4.B8

Cloned(Commentary)

Cloned (Comment)	Organism
recombinant expression of clamp loader complex subunits delta, gamma, delta', chi, and psi	Escherichia coli

Crystallization (Commentary)

Crystallization (Comment)	Organism
determination and analysis of the solution structure of the complete seven subunit clamp loader complex using small angle X-ray scattering (SAXS), modeling, detailed overview. The C-terminal regions of the gamma subunits (residues 374-431) are truncated in the crystal structures because of the flexibility of this region	Escherichia coli

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Mg2+	required	Escherichia coli

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
ATP + H2O	Escherichia coli	-	ADP + phosphate	-	?

Organism

Organism	UniProt	Comment	Textmining
Escherichia coli	P28630 AND P28631 AND P06710 AND P28905 AND P28632	subunits delta, delta', gamma/tau, chi, and psi	-

Purification (Commentary)

Purification (Comment)	Organism
recombinant clamp loader complex subunits delta, gamma, delta', chi, and psi	Escherichia coli

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
ATP + H2O	-	Escherichia coli	ADP + phosphate	-	?
additional information	the three gamma or tau subunits are the active ATPases, and each binds one molecule of ATP	Escherichia coli	?	-	-

Subunits

Subunits	Comment	Organism
heptamer	determination and analysis of the solution structure of the complete seven subunit clamp loader complex using small angle X-ray scattering, modeling, detailed overview. The Escherichia coli core clamp loader contains the five core (delta', delta, and three truncated gamma or tau) subunits, and additionally the psi and chi subunits. The delta subunit is responsible for clamp binding and opening. The d' subunit acts as a stator and stabilizes the interaction of d subunit with the sliding clamp. The tau and gamma subunits are the active ATPases, and both gamma and tau are products of the dnaX gene. The tau and gamma clamp loading function is interchangeable and the major difference is in the length of the two proteins: gamma is a shorter version of s subunits that is created by a translational frame shift. Each DnaX subunit (either tau or gamma) binds one molecule of ATP, and the clamp loader binds and hydrolyses three ATP molecules for each loading cycle. The Escherichia coli clamp loader complex contains two other subunits psi and chi. These two subunits form a tight 1:1 elongated heterodimeric complex. The psi subunit interacts with the C-terminal region of gamma subunit. These two subunits are essential for bridging the interaction between the clamp loader and single strand DNA binding protein (SSB) in Escherichia coli. The psi subunit plays a role in stabilizing the conformational changes induced by ATP binding, the chi subunit directly interacts with the C-terminus of SSB (8 amino acid residues), and the interaction of SSB with chi subunit is increased thousand of folds when SSB is bound to DNA. The chipsi complex also plays a role in increasing the affinity of tau and gamma for delta/delta' to a physiologically relevant range	Escherichia coli

Synonyms

Synonyms	Comment	Organism
clamp loader complex	-	Escherichia coli

General Information

General Information	Comment	Organism
evolution	the clamp loader complex is a member of the AAA+ family of ATPases (adenosine 5'-triphosphatases)	Escherichia coli
additional information	Escherichia coli clamp loader complex is comprised of seven subunits, each of these has critical roles in the function of the clamp loader. Determination and analysis of the solution structure of the complete seven subunit clamp loader complex using small angle X-ray scattering, model of the dynamic nature of the clamp loader complex, overview	Escherichia coli
physiological function	the clamp loader utilizes ATP binding and hydrolysis to load the sliding clamp onto the DNA at the primer template junction	Escherichia coli

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Release 2023.1 (January 2023)