Premium
Crystal structure of human ISG20, an interferon‐induced antiviral ribonuclease
Author(s) -
Horio Tatsuya,
Murai Masatoshi,
Inoue Toshihiko,
Hamasaki Tomohiro,
Tanaka Teruo,
Ohgi Tadaaki
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2004.09.074
Subject(s) - ribonuclease , interferon , virology , chemistry , biology , computational biology , biochemistry , rna , gene
ISG20 is an interferon‐induced antiviral exoribonuclease that acts on single‐stranded RNA and also has minor activity towards single‐stranded DNA. It belongs to the DEDDh group of RNases of the DEDD exonuclease superfamily. We have solved the crystal structure of human ISG20 complexed with two Mn 2+ ions and uridine 5 ′ ‐monophosphate (UMP) at 1.9 Å resolution. Its structure, including that of the active site, is very similar to those of the corresponding domains of two DEDDh‐group DNases, the ε subunit of Escherichia coli DNA polymerase III and E. coli exonuclease I, strongly suggesting that its catalytic mechanism is identical to that of the two DNases. However, ISG20 also has distinctive residues, Met14 and Arg53, to accommodate hydrogen bonds with the 2 ′ ‐OH group of the UMP ribose, and these residues may be responsible for the preference of ISG20 for RNA substrates.