Summary information and primary citation
- PDB-id
-
1zbl;
SNAP-derived features in text and
JSON formats
- Class
- hydrolase-RNA-DNA
- Method
- X-ray (2.2 Å)
- Summary
- Bacillus halodurans rnase h catalytic domain mutant
d192n in complex with 12-mer RNA-DNA hybrid
- Reference
-
Nowotny M, Gaidamakov SA, Crouch RJ, Yang W (2005):
"Crystal
Structures of RNase H Bound to an RNA/DNA Hybrid:
Substrate Specificity and Metal-Dependent Catalysis."
Cell(Cambridge,Mass.), 121,
1005-1016. doi: 10.1016/j.cell.2005.04.024.
- Abstract
- RNase H belongs to a nucleotidyl-transferase
superfamily, which includes transposase, retroviral
integrase, Holliday junction resolvase, and RISC nuclease
Argonaute. We report the crystal structures of RNase H
complexed with an RNA/DNA hybrid and a mechanism for
substrate recognition and two-metal-ion-dependent
catalysis. RNase H specifically recognizes the A form RNA
strand and the B form DNA strand. Structure comparisons
lead us to predict the catalytic residues of Argonaute and
conclude that two-metal-ion catalysis is a general feature
of the superfamily. In nucleases, the two metal ions are
asymmetrically coordinated and have distinct roles in
activating the nucleophile and stabilizing the transition
state. In transposases, they are symmetrically coordinated
and exchange roles to alternately activate a water and a
3'-OH for successive strand cleavage and transfer by a
ping-pong mechanism.
