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  • G9a Methyltransferase


    G9a Methyltransferase methylates lysine 9 (Lys 9) of histone H3 (1-3). Methylation occurs at the ε amino group of lysine residues. Methylation of histone H3 Lys 9 is a hallmark of silent chromatin and is globally distributed throughout the heterochromatic regions, such as centromeres and telomeres (4,5).

    Product Source

    G9a enzyme is expressed from mouse G9a cDNA using an E. coli GST fusion expression system.

    Reagents Supplied

    The following reagents are supplied with this product:

    Store at (°C)Concentration
    S-adenosylmethionine (SAM)-2032 mM
    HMT Reaction Buffer10X

    Properties and Usage

    Unit Definition

    One unit is defined as the amount of enzyme required to catalyze the transfer of 1 pmol of methyl group to synthetic peptide substrate representing the first 17 amino acids of histone H3 in a total reaction volume of 25 µl in 10 minutes at 37°C.

    Reaction Conditions

    1X HMT Reaction Buffer
    Supplement with 160 μM S-adenosylmethionine (SAM)
    Incubate at 37°C

    1X HMT Reaction Buffer:
    50 mM Tris-HCl
    5 mM MgCl2
    4 mM DTT
    pH 9 @ 25°C

    Storage Temperature


    Storage Conditions

    50 mM Tris-HCl
    100 mM NaCl
    5 mM MgCl2
    4 mM DTT
    50% Glycerol
    pH 8.0 @ 25°C

    Heat Inactivation

    65°C for 20 min

    Quality Control

    Quality Assurance Statement

    • Purified free of contaminating proteases.


    1. Storage Note: S-adenosylmethionine (SAM) is stored at -20°C as a 32 mM stolution dissolved in 0.005 M sulfuric acid and 10% ethanol (pH 7.5). Under these conditions, SAM is stable for up to 6 months. SAM is unstable at 37°C and should be replenished in reactions incubated longer than 4 hours. Methylation can be optimized by using fresh SAM. Avoid freeze/thaw of enzyme.


    1. Tachibana, M. et al. (2001). J. Biol. Chem. 276, 25309-25317.
    2. Patnaik, D et al. (2004). J. Biol. Chem. 279, 53248-53258.
    3. Esteve, P.O. et al. (2005). Nucl. Acids. Res. 33, 3211-3223.
    4. Strahl and Allis (2000). Nature. 403, 41-45.
    5. Noma, K. et al. (2001). Science . 293, 1150-1155.

    Supporting Documents

    Material Safety Datasheets

    The following is a list of Material Safety Data Sheets (MSDS) that apply to this product to help you use it safely. The following file naming structure is used to name these document files: [Product Name] MSDS. For international versions please contact us at info@neb.com.


    The Product Summary Sheet, or Data Card, includes details for how to use the product, as well as details of its formulation and quality controls. The following file naming structure is used to name the majority of these document files: [Catalog Number]Datasheet-Lot[Lot Number]. For those product lots not listed below, please contact NEB at info@neb.com or fill out the Technical Support Form for appropriate document.