1rgt
From Proteopedia
Crystal structure of human Tyrosyl-DNA Phosphodiesterase complexed with vanadate, octopamine, and tetranucleotide AGTC
Structural highlights
Disease[TYDP1_HUMAN] Defects in TDP1 are the cause of spinocerebellar ataxia autosomal recessive with axonal neuropathy (SCAN1) [MIM:607250]. SCAN1 is an autosomal recessive cerebellar ataxia (ARCA) associated with peripheral axonal motor and sensory neuropathy, distal muscular atrophy, pes cavus and steppage gait as seen in Charcot-Marie-Tooth neuropathy. All affected individuals have normal intelligence.[1] [2] [3] [4] [5] Function[TYDP1_HUMAN] DNA repair enzyme that can remove a variety of covalent adducts from DNA through hydrolysis of a 3'-phosphodiester bond, giving rise to DNA with a free 3' phosphate. Catalyzes the hydrolysis of dead-end complexes between DNA and the topoisomerase I active site tyrosine residue. Hydrolyzes 3'-phosphoglycolates on protruding 3' ends on DNA double-strand breaks due to DNA damage by radiation and free radicals. Acts on blunt-ended double-strand DNA breaks and on single-stranded DNA. Has low 3'exonuclease activity and can remove a single nucleoside from the 3'end of DNA and RNA molecules with 3'hydroxyl groups. Has no exonuclease activity towards DNA or RNA with a 3'phosphate.[6] [7] [8] [9] [10] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedTyrosyl-DNA phosphodiesterase (Tdp1) catalyzes the hydrolysis of a phosphodiester bond between a tyrosine residue and a DNA 3' phosphate and functions as a DNA repair enzyme that cleaves stalled topoisomerase I-DNA complexes. We previously determined a procedure to crystallize a quaternary complex containing Tdp1, vanadate, a DNA oligonucleotide, and a tyrosine-containing peptide that mimics the transition state for hydrolysis of the Tdp1 substrate. Here, the ability of vanadate to accept a variety of different ligands is exploited to produce several different quaternary complexes with a variety of oligonucleotides, and peptides or a tyrosine analogue, in efforts to explore the binding properties of the Tdp1 DNA and peptide binding clefts. Eight crystal structures of Tdp1 with vanadate, oligonucleotides, and peptides or peptide analogues were determined. These structures demonstrated that Tdp1 is able to bind substituents with limited sequence variation in the polypeptide moiety and also bind oligonucleotides with sequence variation at the 3' end. Additionally, the tyrosine analogue octopamine can replace topoisomerase I derived peptides as the apical ligand to vanadate. The versatility of this system suggests that the formation of quaternary complexes around vanadate could be adapted to become a useful method for structure-based inhibitor design and has the potential to be generally applicable to other enzymes that perform chemistry on phosphate esters. Explorations of peptide and oligonucleotide binding sites of tyrosyl-DNA phosphodiesterase using vanadate complexes.,Davies DR, Interthal H, Champoux JJ, Hol WG J Med Chem. 2004 Feb 12;47(4):829-37. PMID:14761185[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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