4NSP: Crystal Structure Of Human Endov

Citation:
Acta Crystallogr. D Biol. Crystallogr. (2014) 70 p.2286-2294
Abstract
The 6-aminopurine ring of adenosine (A) can be deaminated to form the 6-oxopurine of inosine (I). Endonuclease Vs (EndoVs) are inosine-specific nucleases that cleave at the second phosphodiester bond 3' to inosine. EndoV proteins are highly conserved in all domains of life, but the bacterial and human enzymes seem to display distinct substrate preferences. While the bacterial enzymes exhibit high cleavage efficiency on various nucleic acid substrates, human EndoV (hEndoV) is most active towards ssRNA but is much less active towards other substrates. However, the structural basis of substrate recognition by hEndoV is not well understood. In this study, the 2.3 A resolution crystal structure of hEndoV was determined and its unusual RNA-cleaving properties were investigated. The enzyme preserves the general `RNase H-like' structure, especially in the wedge motif, the metal-binding site and the hypoxanthine-binding pocket. hEndoV also features several extra insertions and a characteristic four-cysteine motif, in which Cys227 and Cys228, two cysteines that are highly conserved in higher eukaryotes, play important roles in catalysis. The structure presented here helps in understanding the substrate preference of hEndoV catalysis.
PDB ID: 4NSPDownload
MMDB ID: 123017
PDB Deposition Date: 2013/11/28
Updated in MMDB: 2014/10
Experimental Method:
x-ray diffraction
Resolution: 2.3  Å
Source Organism:
Similar Structures:
Biological Unit for 4NSP: monomeric; determined by author and by software (PISA)
Molecular Components in 4NSP
Label Count Molecule
Protein (1 molecule)
1
Endonuclease V(Gene symbol: ENDOV)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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