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Catalytic center of an archaeal type 2 ribonuclease H as revealed by X‐ray crystallographic and mutational analyses
Author(s) -
Muroya Ayumu,
Tsuchiya Daisuke,
Ishikawa Momoyo,
Haruki Mitsuru,
Morikawa Masaaki,
Kanaya Shigenori,
Morikawa Kosuke
Publication year - 2001
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.48001
Subject(s) - rnase p , thermococcus , rnase h , rnase ph , s tag , biology , histidine , transferase , ribonuclease iii , dna , ribonuclease , stereochemistry , crystallography , enzyme , genetics , rna , chemistry , biochemistry , archaea , gene , rna interference
Abstract The catalytic center of an archaeal Type 2 RNase H has been identified by a combination of X‐ray crystallographic and mutational analyses. The crystal structure of the Type 2 RNase H from Thermococcus kodakaraensis KOD1 has revealed that the N‐terminal major domain adopts the RNase H fold, despite the poor sequence similarity to the Type 1 RNase H. Mutational analyses showed that the catalytic reaction requires four acidic residues, which are well conserved in the Type 1 RNase H and the members of the polynucleotidyl transferase family. Thus, the Type 1 and Type 2 RNases H seem to share a common catalytic mechanism, except for the requirement of histidine as a general base in the former enzyme. Combined with the results from deletion mutant analyses, the structure suggests that the C‐terminal domain of the Type 2 RNase H is involved in the interaction with the DNA/RNA hybrid.