Exonucleases (ExN) cleave nucleotides at the end of a polynucleotide chain[1]. In E. coli there are ExN I to VIII.

  • ExN-I cleaves single-stranded DNA.
  • ExN-II is associated with DNA polymerase.
  • ExN-III cleaves double-stranded DNA.
  • ExN-IV cleavage results in nucleoside monophosphate.
  • ExN-V cleaves linear double-stranded DNA.
  • ExN-VIII requires a free 5’ OH group for reacting.
  • ExN were found in human and yeast as well.

E. coli exonuclease I complex with phosphate, glycerol and Mg+2 ion (PDB code 1fxx)

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3D Structures of exonuclease3D Structures of exonuclease

Updated on 20-January-2016

ReferencesReferences

  1. Athappilly FK, Hendrickson WA. Structure of the biotinyl domain of acetyl-coenzyme A carboxylase determined by MAD phasing. Structure. 1995 Dec 15;3(12):1407-19. PMID:8747466

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