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  • pKLAC2 Vector


    The vector pKLAC2 directs high-level expression of a recombinant protein from the yeast Kluyveromyces lactis and is compatible with the K. lactis Protein Expression Kit (NEB #E1000). pKLAC2 can be used for either intracellular or secreted protein expression. SacII or BstXI linearized pKLAC2 integrates into the LAC4 locus of the K. lactis genome upon transformation of K. lactis competent cells. pKLAC2 differs from pKLAC1 (>NEB #N3740) in that it contains a universal multiple cloning site (MCS) that is compatible with all NEB expression systems.

    Vector pKLAC2 contains the strong K. lactis PLAC4-PBI promoter (1), DNA encoding the K. lactis α-mating factor (α-MF) secretion domain (for secreted expression), a universal multiple cloning site (MCS), the K. lactis LAC4 transcription terminator (TT), and a fungal acetamidase selectable marker gene (amdS) expressed from the yeast ADH1 promoter (PADH1). An E. coli replication origin (ori) and ampicillin resistance gene (ApR) are present for propagation of pKLAC2 in E. coli.

    The sequence of the pKLAC2 vector (GenBank #EU196354) and additional pKLAC2 information are available at DNA Sequences and Maps.

    DNASU is a central repository for plasmid clones and collections that may also be helpful.


    • PLAC4-PBI promoter does not express in E. coli allowing toxic genes to be cloned prior to their expression in yeast.
    • Universal MCS lies downstream of α-MF secretion domain and PLAC4-PBI promoter.
    • Acetamidase expression for non-antibiotic selection in K. lactis.
    • Ampicillin resistance for propagation in E. coli. (See notes.)

    Properties and Usage

    Affinity Tag


    Storage Temperature



    1. NEB5-alpha Competent E.coli (High Efficiency) (NEB #C2987), NEB 5-alpha Electrocompetent E. coli (NEB #C2989) and NEB 5-alpha Competent E. coli (Subcloning Efficiency) (NEB #C2988J) are all recommended for propagation and subcloning this vector.


    1. Colussi, P.A. and Taron, C.H. (2005). Appl. Environ. Microbiol.. 71, 7092-7098.

    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.

    Interactive Tools

    Application Notes