IUBMB Enzyme Nomenclature


Accepted name: 5' to 3' exodeoxyribonuclease (nucleoside 3'-phosphate-forming)

Reaction: exonucleolytic cleavage in the 5'- to 3'-direction to yield nucleoside 3'-phosphates

Other name(s): Cas4; 5' to 3' single stranded DNA exonuclease

Comments: Preference for single-stranded DNA. The enzyme from the archaeon Sulfolobus solfataricus contains a [4Fe-4S] cluster and requires a divalent metal cation, such as Mg2+ or Mn2+, for activity.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:


1. Zhang, J., Kasciukovic, T. and White, M.F. The CRISPR associated protein Cas4 Is a 5' to 3' DNA exonuclease with an iron-sulfur cluster. PLoS One 7 (2012) e47232. [PMID: 23056615]

2. Lemak, S., Beloglazova, N., Nocek, B., Skarina, T., Flick, R., Brown, G., Popovic, A., Joachimiak, A., Savchenko, A. and Yakunin, A.F. Toroidal structure and DNA cleavage by the CRISPR-associated [4Fe-4S]-cluster containing Cas4 nuclease SSO0001 from Sulfolobus solfataricus. J. Am. Chem. Soc. 135 (2013) 17476-17487. [PMID: 24171432]

[EC created 2014]

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