22 ホモポリアミノ酸ε-Poly-L-lysineを合成する新奇非リボソームペプチド合成酵素(口頭発表の部)

DOI

書誌事項

タイトル別名
  • 22 Novel peptide synthase producing homo poly-amino acid, ε-Poly-L-lysine(Oral Presentation)

抄録

Only two different amino-acid "homopolymers" comprised of a single type of amino acid are known in nature: γ-poly-glutamic acid (γ-PGA) and ε-poly-L-lysine (ε-PL). ε-PL consisting of 25-35 L-lysine residues in isopeptide linkages has shown promise in medical and industrial applications. Elucidating the biosynthetic mechanism of ε-PL should open new avenues for creating novel classes of biopolymers. Here we report on the purification of an ε-PL synthase (Pls; 130kDa) and the cloning of its gene from an ε-PL-producing strain of Streptowyces albulus. Pls was found to be a membrane protein with six transmembrane domains. It was shown to be a single-module nonribosomal peptide synthase (NRPS) with traditional adenylation (A-domain) and thiolation domains (T-domain) in its amino (N)-terminal region. It had no traditional condensation or thioesterase domain; instead, it had three tandem carboxy (C)-terminal acyltransferase domains that catalysed L-lysine polymerization iteratively, yielding chains of diverse length (3-mer to 17-mer) in vitro. Furthermore, these domains catalysed the condensation of free L-lysine monomers (or ε-PL oligomers) as acceptors with enzyme-bound L-lysine as a donor; hence, L-lysine activated by the A-domain and T-domain was used only as an extender unit. A database search showed that Pls homologues were widely distributed among microorganisms and that amino-acid homopolymers, in addition to ε-PL and γ-PGA, might occur in nature.

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詳細情報 詳細情報について

  • CRID
    1390001206078663552
  • NII論文ID
    110007066647
  • DOI
    10.24496/tennenyuki.50.0_155
  • ISSN
    24331856
  • 本文言語コード
    ja
  • データソース種別
    • JaLC
    • CiNii Articles
  • 抄録ライセンスフラグ
    使用不可

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