1oe6
From Proteopedia
| Line 5: | Line 5: | ||
==Overview== | ==Overview== | ||
| - | Cytosine deamination is a major promutagenic process, generating G:U, mismatches that can cause transition mutations if not repaired. Uracil is, also introduced into DNA via nonmutagenic incorporation of dUTP during, replication. In bacteria, uracil is excised by uracil-DNA glycosylases, (UDG) related to E. coli UNG, and UNG homologs are found in mammals and, viruses. Ung knockout mice display no increase in mutation frequency due, to a second UDG activity, SMUG1, which is specialized for antimutational, uracil excision in mammalian cells. Remarkably, SMUG1 also excises the, oxidation-damage product 5-hydroxymethyluracil (HmU), but like UNG is, inactive against thymine (5-methyluracil), a chemical substructure of HmU., We have solved the crystal structure of SMUG1 complexed with DNA and, . | + | Cytosine deamination is a major promutagenic process, generating G:U, mismatches that can cause transition mutations if not repaired. Uracil is, also introduced into DNA via nonmutagenic incorporation of dUTP during, replication. In bacteria, uracil is excised by uracil-DNA glycosylases, (UDG) related to E. coli UNG, and UNG homologs are found in mammals and, viruses. Ung knockout mice display no increase in mutation frequency due, to a second UDG activity, SMUG1, which is specialized for antimutational, uracil excision in mammalian cells. Remarkably, SMUG1 also excises the, oxidation-damage product 5-hydroxymethyluracil (HmU), but like UNG is, inactive against thymine (5-methyluracil), a chemical substructure of HmU., We have solved the crystal structure of SMUG1 complexed with DNA and, base-excision products. This structure indicates a more invasive, interaction with dsDNA than observed with other UDGs and reveals an, elegant water displacement/replacement mechanism that allows SMUG1 to, exclude thymine from its active site while accepting HmU. |
==About this Structure== | ==About this Structure== | ||
| - | 1OE6 is a | + | 1OE6 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis] with HMU, GOL and IPA as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1OE6 OCA]. |
==Reference== | ==Reference== | ||
| Line 23: | Line 23: | ||
[[Category: smug1]] | [[Category: smug1]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 13:27:41 2007'' |
Revision as of 11:22, 5 November 2007
|
XENOPUS SMUG1, AN ANTI-MUTATOR URACIL-DNA GLYCOSYLASE
Overview
Cytosine deamination is a major promutagenic process, generating G:U, mismatches that can cause transition mutations if not repaired. Uracil is, also introduced into DNA via nonmutagenic incorporation of dUTP during, replication. In bacteria, uracil is excised by uracil-DNA glycosylases, (UDG) related to E. coli UNG, and UNG homologs are found in mammals and, viruses. Ung knockout mice display no increase in mutation frequency due, to a second UDG activity, SMUG1, which is specialized for antimutational, uracil excision in mammalian cells. Remarkably, SMUG1 also excises the, oxidation-damage product 5-hydroxymethyluracil (HmU), but like UNG is, inactive against thymine (5-methyluracil), a chemical substructure of HmU., We have solved the crystal structure of SMUG1 complexed with DNA and, base-excision products. This structure indicates a more invasive, interaction with dsDNA than observed with other UDGs and reveals an, elegant water displacement/replacement mechanism that allows SMUG1 to, exclude thymine from its active site while accepting HmU.
About this Structure
1OE6 is a Protein complex structure of sequences from Xenopus laevis with HMU, GOL and IPA as ligands. Structure known Active Site: AC1. Full crystallographic information is available from OCA.
Reference
Structure and specificity of the vertebrate anti-mutator uracil-DNA glycosylase SMUG1., Wibley JE, Waters TR, Haushalter K, Verdine GL, Pearl LH, Mol Cell. 2003 Jun;11(6):1647-59. PMID:12820976
Page seeded by OCA on Mon Nov 5 13:27:41 2007
Categories: Protein complex | Xenopus laevis | Pearl, L.H. | Wibley, J.E.A. | GOL | HMU | IPA | Dna glycosylase | Single stranded | Smug1
