'Star' activity and complete loss of specificity of CeqI endonuclease

Z. Izsvak, E. Duda

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Restriction endonuclease CeqI, an isoschizomer of EcoRV, exhibits 'star' activity, a relaxation of specificity in the presence of Mn2+, dimethyl sulphoxide or glycerol. The enzyme cleaves a set of sequences that differ from the canonical GATATC by only one nucleotide in positions 2, 3, 4 or 5. Two of these sequences are not cleaved if modified by dam methylase. A further loss of specificity can be observed in circumstances less favourable for the enzyme, namely low-ionic-strength buffers of pH values below 6.0 or above 9.4. This activity seems to cleave DNA at any sequence, producing a smear instead of well-defined bands. Partial renaturation of the denatured enzyme gives rise to a similar non-specific nuclease activity.

Original languageEnglish
Pages (from-to)301-303
Number of pages3
JournalBiochemical Journal
Volume258
Issue number1
Publication statusPublished - 1989

Fingerprint

Stars
Enzymes
DNA Restriction Enzymes
Dimethyl Sulfoxide
Ionic strength
Osmolar Concentration
Glycerol
Buffers
Nucleotides
DNA
GATATC-specific type II deoxyribonucleases
Dam methyltransferase

ASJC Scopus subject areas

  • Biochemistry

Cite this

'Star' activity and complete loss of specificity of CeqI endonuclease. / Izsvak, Z.; Duda, E.

In: Biochemical Journal, Vol. 258, No. 1, 1989, p. 301-303.

Research output: Contribution to journalArticle

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