Topo I (Y723F) (mt Y723F) human
SIGMA/SRP2035 - recombinant, expressed in insect cells, ≥80% (SDS-PAGE)
Synonym: TOPI
Product Type: Chemical
Immunoblotting Topo I (Y723F) (mt Y723F) Cat. No. SRP2035: Topo I (Y723F) (mt Y723F) was separated on SDS-PAGE using 1-3 μg protein (left); and a protein marker (right).
| assay | ≥80% (SDS-PAGE) |
| biological source | human |
| color | clear colorless |
| concentration | 1000 μg/mL |
| form | frozen liquid |
| mol wt | ~92.4 kDa |
| NCBI accession no. | NM_003286   |
| packaging | pkg of 5 μg |
| recombinant | expressed in insect cells |
| shipped in | dry ice |
| storage condition | avoid repeated freeze/thaw cycles |
| storage temp. | −70°C |
| UniProt accession no. | P11387 |
| Biochem/physiol Actions: | Human DNA topoisomerase I is the best studied of the DNA topoisomerase family. It catalyzes the relaxation of both positive and negative supercoiled DNAs 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, cell cycle and other gene regulatory pathways during cell growth and development. Tyrosine 723 was identified as an active site for the DNA binding activity of DNA topoisomerase I. The covalent intermediate of topo I and DNA complex includes nucleophilic attack by the O4-oxygen of tyrosine 723 on a phosphester linkage in the DNA. Mutation from tyrosine to phenylalanine at position 723 preferentially binds the supercoiled DNA rather than relaxed DNA in the mixture of supercoiled and relaxed DNAs. But mutation at tyr723 neither affects its kinase activity that phosphorylates splicing factors of SR protein family nor its transcription activity of class II genes in vitro. |
| 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. |
| RIDADR | NONH for all modes of transport |
| WGK Germany | WGK 1 |
| Flash Point(F) | Not applicable |
| Flash Point(C) | Not applicable |
| Purity | ≥80% (SDS-PAGE) |
| Storage Temp. | −70°C |
| UNSPSC | 12352200 |