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PDBsum entry 1vsr
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Crystallographic and functional studies of very short patch repair endonuclease.
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Authors
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S.E.Tsutakawa,
T.Muto,
T.Kawate,
H.Jingami,
N.Kunishima,
M.Ariyoshi,
D.Kohda,
M.Nakagawa,
K.Morikawa.
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Ref.
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Mol Cell, 1999,
3,
621-628.
[DOI no: ]
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PubMed id
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Abstract
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Vsr endonuclease plays a crucial role in the repair of TG mismatched base pairs,
which are generated by the spontaneous degradation of methylated cytidines; Vsr
recognizes the mismatched base pair and cleaves the phosphate backbone 5' to the
thymidine. We have determined the crystal structure of a truncated form of this
endonuclease at 1.8 A resolution. The protein contains one structural
zinc-binding module. Unexpectedly, its overall topology resembles members of the
type II restriction endonuclease family. Subsequent mutational and biochemical
analyses showed that certain elements in the catalytic site are also conserved.
However, the identification of a critical histidine and evidence of an active
site metal-binding coordination that is novel to endonucleases indicate a
distinct catalytic mechanism.
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Figure 3.
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Figure 4.
Figure 4. Similarity of Topology to Restriction Type II
Endonucleases(A–C) Ribbon diagrams of (A) Vsr, (B) one subunit
of BamHI ([32]), and (C) one subunit of EcoRV ( [46]) after
superimposition of the side chain of the first conserved
aspartate in the conserved catalytic motif and overlaying β
strands. Figures were derived from 1bhm and 1rvb. Side chains
important for endonuclease activity are depicted. Carbon,
oxygen, and nitrogen atoms are depicted in green, red, and blue,
respectively.(D) Enlarged view of superimposed Vsr (blue), BamHI
(brown), and EcoRV (green) active sites, with side chains from
the active site motif displayed.
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The above figures are
reprinted
by permission from Cell Press:
Mol Cell
(1999,
3,
621-628)
copyright 1999.
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