A new Thermus sp. class-IIS enzyme sub-family: isolation of a 'twin' endonuclease TspDTI with a novel specificity 5'-ATGAA(N(11/9))-3', related to TspGWI, TaqII and Tth111II

Nucleic Acids Res. 2003 Jul 15;31(14):e74. doi: 10.1093/nar/gng074.

Abstract

The TspDTI restriction endonuclease, which shows a novel recognition specificity 5'-ATGAA(N(11/9))-3', was isolated from Thermus sp. DT. TspDTI appears to be a 'twin' of restriction endonuclease TspGWI from Thermus sp. GW, as we have previously reported. TspGWI was isolated from the same location as TspDTI, it recognizes a related sequence 5'-ACGGA(N(11/9))-3' and has conserved cleavage positions. Both enzymes resemble two other class-IIS endonucleases from Thermus sp.: TaqII and Tth111II. N-terminal amino acid sequences of TspGWI tryptic peptides exhibit 88.9-100% similarity to the TaqII sequence. All four enzymes were purified to homogeneity; their polypeptide sizes (114.5-122 kDa) make them the largest class-IIS restriction endonucleases known to date. The existence of a Thermus sp. sub-family of class-IIS restriction endonucleases of a common origin is herein proposed.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites / genetics
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Deoxyribonucleases, Type II Site-Specific / genetics
  • Deoxyribonucleases, Type II Site-Specific / isolation & purification
  • Deoxyribonucleases, Type II Site-Specific / metabolism*
  • Evolution, Molecular
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Substrate Specificity
  • Thermus / enzymology*
  • Thermus / genetics

Substances

  • DNA, Bacterial
  • endodeoxyribonuclease TaqII
  • endodeoxyribonuclease Tth111II
  • Deoxyribonucleases, Type II Site-Specific