Cloning and Sequencing of the pelCl Gene Encoding Pectate Lyase of Erwinia carotovora subsp. carotovora LY34

Erwinia carotovora subsp. carotovora LY34에서 pelCI 유전자 클로닝

  • Lim, Sun-Tech (Department of Agricultural Chemistry, Gyeongsang National University) ;
  • Park, Yong-Woo (Department of Agricultural Chemistry, Gyeongsang National University) ;
  • Yun, Han-Dae (Department of Agricultural Chemistry, Gyeongsang National University)
  • Published : 1997.10.31

Abstract

Phytopathogenic Erwinia carotovora subsp. carotovora (Ecc) LY34 causes plant tissue maceration by secretion of pectinolytic enzymes such as pectate Iyase (PL) existed as multiple isoenzyme form. Genomic DNA from Ecc LY34 was digested with Sau3Al and ligated into the BamHI site of pBluescript ll $SK^+$. Among them, a clone hydrolyzing polypectate was selected and its DNA was digested with BamHI. Through the subsequent subcloning the resulting 3.1 kb fragment, corresponding to a peICI, was subcloned into pLYPA 100. The structural organization of a peICI gene encoding a 374 amino acid residues consists of an open reading frame (ORF) of 1,122 bp commencing with a ATG start codon and followed by a TAA stop codon. PeICI contained a typical prokaryotic signal peptide of 22-amino acid. Since the deduced amino acid sequences of PeICl protein was very similar to those of PelIII of Erwinia carotovora subsp. carotovora, and to those of Pel3 of Erwinia carotovora subsp. atroseptica, and to those of PeIC of Erwinia carotovora subsp. carotovora, it belong to the same family PLbc group. The 374-amino acld PeICI had a calculated Mr of 40,507 and pI of 7.60.

Pectate lyase isoenzymes을 분비하는 Erwinia carotovorn subsp. carotovora LY34는 식물조직을 연화시키는 연부균이다. 이 균주로부터 게놈 DNA를 분리하여 Sau3Al 제한효소로 부분 절단한 다음 pBluescript $SK^+$ 벡터에 클로닝하여 pectate Iyase를 분비하는 클론을 분리하였다 분리 결과 4.2 kb크기의 DNA 단편을 가지고 있었으며 이를 다시 재클로닝하여 3.1 kb크기의 pelCI유전자를 함유하는 pLYPA100을 구하였다. 이 유전자의 DNA 염기서열을 분석한 결과 374 개의 아미노산을 구성하는 1,122 bp의 ORF를 확인하였다. 시작코돈과 종결코돈은 ATG와 TAA였으며 초기 서열 22개의 아미노산으로 구성된 전형적인 원핵세포의 signal peptide가 존재하였다. PeICI의 단백질 염기서열을 다른 단백질과 유사성을 분석한 결과 Erwinia carotovera subsp. carotovora Er 균주의 PelIII, Erwinia carotevora subsp. carotovora SCR193 균주의 PeIC 및 Erwinia caretovora subsp. atroseptica C18 균주의 Pel3과 유사하였으며 PLbc family에 속하였다. PeICI의 분자량은 40,507, pI는 7.60으로 계산되었다.

Keywords