Extreme Thermostable Single-Stranded DNA Binding Protein, CAS No.E1520753

CAS: E1520753 Cat. No.: E1520753 Molecular Weight: 16 kDa

GRADE & PURITY Recombinant, DNase, RNase free, PCR Reagent, ≥95%(SDS-PAGE), 500 μg/mL

Accession #

Q9WZ73

Expression system

E. coli

Overview

Extreme Thermostable Single-Strand DNA Binding Protein (ET SSB) is a single-strand DNA binding protein isolated from thermophilic microorganisms, with a molecular weight of 16 kDa. It retains full activity after incubation at 95°C for 60 minutes. Due to its extremely high thermostability, ET SSB can be used in applications requiring very high temperature conditions, such as nucleic acid amplification and sequencing.

ET SSB is a sequence‑independent single‑strand DNA binding protein; it does not bind RNA or double‑stranded DNA. ssDNA is prone to degradation by DNase and the formation of secondary structures, and its instability greatly limits the normal progress of enzymatic reactions. Binding of ET SSB to ssDNA stabilizes and protects single‑stranded DNA from DNase degradation or secondary structure formation, facilitates the binding of DNA polymerase to the substrate, thereby increasing the catalytic activity of DNA polymerase and improving the amplification efficiency of PCR and other reactions.

SSB proteins exist in almost all organisms. Although all SSB proteins have similar functions, they share little sequence similarity and differ significantly in their ssDNA binding properties. Based on their oligomeric state, SSB proteins can be classified into four types: monomers, homodimers, heterotrimers, and homotetramers. ET SSB originates from hyperthermophilic microorganisms and exists mainly as a monomer in solution, with each monomer encoding one OB‑fold domain. It forms dimers or multimers only when binding to single‑stranded DNA substrates.

Applications

1. Increase the processivity of DNA polymerase;

2. Stabilize and label ssDNA structures;

3. Improve the yield and specificity of PCR and isothermal amplification reactions;

4. Enhance the yield and conversion efficiency of reverse transcriptase (RT) during RT‑PCR;

5. Improve DNA sequencing in regions with strong secondary structures;

6. Enhance the activity of RecA in ssDNA binding and strand transfer.

Usage Method

1. ET SSB is active in any polymerase buffer;

2. Add 50–200 ng of ET SSB per 50 μL reaction system.

Quality Control

1. Protein Purity Assay

   SDS‑PAGE analysis shows protein purity ≥95%.

2. Endonuclease Activity Assay

   After incubating 0.5 μg ET SSB with 200 ng of supercoiled plasmid DNA at 37°C for 4 hours, agarose gel electrophoresis detects that less than 10% of the plasmid DNA is converted to nicked or linear forms.

3. Non‑Specific Nuclease Activity Assay

   After incubating 0.5 μg ET SSB with 15 ng of double‑stranded DNA fragments at 37°C for 16 hours, agarose gel electrophoresis shows no change in the double‑stranded DNA substrate.

4. Host DNA Residue Detection

   Using E. coli 16S rDNA‑specific primer/probe sets and real‑time PCR, the residual E. coli host genomic DNA in 0.5 μg ET SSB is less than 10 copies.

Precautions

1. This product is for professional scientific research use only. It must not be used for clinical diagnosis or treatment, nor for food or drug purposes, nor stored in ordinary residential areas.

2. For your safety and health, wear a lab coat and disposable gloves during handling.

Specifications

Product Name

Extreme Thermostable Single-Stranded DNA Binding Protein, CAS No.E1520753

Synonyms

ET SSB | Thermostable SSB

Grade

DNase, RNase free, PCR Reagent, Recombinant

Specifications & Purity

DNase, RNase free, PCR Reagent, Recombinant, ≥95%(SDS-PAGE), 500 μg/mL

Accession #

Q9WZ73

Predicted molecular weight

16 kDa

CAS

E1520753

Molecule Type

Protein

Storage and Shipping

Concentration

500 μg/mL

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Stability And Storage

Store at -20℃ long term (24 months). Upon receipt, it is recommended to aliquot. Avoid freeze/thaw cycle.

Frequently Asked Questions

What does BioReagent mean?

BioReagent indicates that the product has been processed and tested for biological and biochemical applications. Specifications may include endotoxin limits, microbial controls, sterility, low DNase/RNase/protease activity, and verified biological activity where relevant.