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PDBsum entry 1zbf
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References listed in PDB file
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Key reference
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Title
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Crystal structures of rnase h bound to an rna/DNA hybrid: substrate specificity and metal-Dependent catalysis.
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Authors
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M.Nowotny,
S.A.Gaidamakov,
R.J.Crouch,
W.Yang.
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Ref.
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Cell, 2005,
121,
1005-1016.
[DOI no: ]
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PubMed id
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Abstract
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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.
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Figure 2.
Figure 2. Structure and Sequence Comparison of Bh, E. coli,
and HIV RNases H
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Figure 5.
Figure 5. The Active Site
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The above figures are
reprinted
by permission from Cell Press:
Cell
(2005,
121,
1005-1016)
copyright 2005.
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