ABC Transporter Genes, kasKLM, Responsible for Self-resistance of a Kasugamycin Producer Strain

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Abstract

We previously reported that a 7.6-kb DNA fragment from <i>Streptomyces kasugaensis</i> M338-M1, a kasugamycin (KSM) producer, included KSM acetyltransferase gene (<i>kac</i><sup>338</sup>) and some other genes possibly involved in KSM biosynthesis. As an extension of that study, a 10-kb <i>Sac</i>I-<i>Kpn</i>I DNA fragment, located 5-15-kb upstream of <i>kac</i><sup>338</sup>, was cloned and a 4.2-kb <i>Sac</i>I-<i>Eco</i>RI fragment therefrom was sequenced, revealing one incomplete (designated ORF J) and three complete open reading frames (designated <i>kasK</i>, <i>kasL</i> and <i>kasM</i>). The coding frames of <i>kasK</i>, <i>L</i> and <i>M</i> overlap one another with terminator/initiator ATGA sequence. RT-PCR analysis of a DNA region including <i>kasKLM</i> indicated the presence of one transcript that is long enough to span the three genes. The <i>kasK</i> gene potentially encodes an ATP-binding protein of the ATP-binding cassette (ABC) transporter superfamily. Homology search for the deduced KasK protein shows similarity to other ABC transporters involved in self-resistance of a mithramycin and possibly doxorubicin producer strain. The <i>kasL</i> and <i>kasM</i> genes encode different integral membrane proteins, both having six putative transmembrane helices. An expression plasmid for <i>kasKLM</i> (pTV-KLM) was constructed and these genes were expressed in <i>E. coli</i> JM109, which had been sensitive to KSM. The transformant acquired resistance to KSM, suggesting that KasK, L and M proteins as a set in <i>S. kasugaensis</i> M338-M1 pump out KSM to protect the producer from its toxic metabolite.

Journal

  • The Journal of Antibiotics

    The Journal of Antibiotics 53(4), 373-384, 2000-04-25

    JAPAN ANTIBIOTICS RESEARCH ASSOCIATION

References:  33

Cited by:  1

Codes

  • NII Article ID (NAID)
    10008466657
  • NII NACSIS-CAT ID (NCID)
    AA0069330X
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    00218820
  • Data Source
    CJP  CJPref  J-STAGE 
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