Structural parsimony in endonuclease active sites: should the number of homing endonuclease families be redefined?

FEBS Letters

Hemmings, Andrew M.²  Kühlmann, Ulrike C.²  James, Richard¹  Kleanthous, Colin¹  Moore, Geoffrey R.² 

[1] School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK;School of Chemical Sciences, University of East Anglia, Norwich NR4 7TJ, UK

关键词: Colicin E9;    Nuclease active site motif;    Homing endonuclease;   

DOI  :  10.1016/S0014-5793(99)01499-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Homing endonucleases are classified into four families based on active site sequence motifs. Through structural comparisons we have found structural similarities between the endonuclease domain of colicin E9, an H-N-H motif-containing enzyme, and both the non-specific nuclease from Serratia and I-PpoI, a His-Cys box-containing homing endonuclease. Our comparison identifies conservation at the heart of all three enzyme active sites and so argues for a re-classification of H-N-H and His-Cys box homing endonucleases as a single family. We suggest the ‘ββα-Me family’ of homing enzymes to reflect the three elements of secondary structure and the metal ion that define the motif.

【 授权许可】

Unknown