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SRP2032

Sigma-Aldrich

Topo I (C651-765) (C terminal domain) human

recombinant, expressed in insect cells, ≥80% (SDS-PAGE)

Synonym(s):

TOPI

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About This Item

UNSPSC Code:
12352202
NACRES:
NA.26

biological source

human

recombinant

expressed in insect cells

Assay

≥80% (SDS-PAGE)

form

frozen liquid

mol wt

~15.2 kDa

packaging

pkg of 5 μg

storage condition

avoid repeated freeze/thaw cycles

concentration

500 μg/mL

color

clear colorless

NCBI accession no.

UniProt accession no.

shipped in

dry ice

storage temp.

−70°C

Gene Information

human ... TOP1(7150)

Biochem/physiol Actions

Human DNA topoisomerase I catalyzes the relaxation of both positive and negative supercoils without the requirement of energy. In addition to DNA replication and transcriptional activation, DNA topoisomerase I also plays a major role in pre-mRNA splicing, recombination, chromatin remodeling and other DNA or RNA templating activities. The C terminal domain of DNA topoisomerase I spanning from amino acids 713 to 765 is highly conserved and connected to the core domain by a poorly conserved linker domain (residues 636-713). An active site tyrosine has been characterized at position 723. Mutation of this tyrosine to phenylalanine at position 723 causes topo I to preferentially bind the supercoiled DNA rather than relaxed DNA in the mixture of supercoiled and relaxed DNA.

Physical form

Clear and colorless frozen liquid solution

Preparation Note

Use a manual defrost freezer and avoid repeated freeze-thaw cycles. While working, please keep sample on ice.

Storage Class Code

10 - Combustible liquids

WGK

WGK 1

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable


Certificates of Analysis (COA)

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M R Redinbo et al.
Science (New York, N.Y.), 279(5356), 1504-1513 (1998-03-21)
Topoisomerases I promote the relaxation of DNA superhelical tension by introducing a transient single-stranded break in duplex DNA and are vital for the processes of replication, transcription, and recombination. The crystal structures at 2.1 and 2.5 angstrom resolution of reconstituted
DNA topoisomerase poisons as antitumor drugs.
L F Liu
Annual review of biochemistry, 58, 351-375 (1989-01-01)
J J Champoux
Annual review of biochemistry, 70, 369-413 (2001-06-08)
DNA topoisomerases solve the topological problems associated with DNA replication, transcription, recombination, and chromatin remodeling by introducing temporary single- or double-strand breaks in the DNA. In addition, these enzymes fine-tune the steady-state level of DNA supercoiling both to facilitate protein

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