1dnp
STRUCTURE OF DEOXYRIBODIPYRIMIDINE PHOTOLYASESTRUCTURE OF DEOXYRIBODIPYRIMIDINE PHOTOLYASE
Structural highlights
Function[PHR_ECOLI] Involved in repair of UV radiation-induced DNA damage. Catalyzes the light-dependent monomerization (300-600 nm) of cyclobutyl pyrimidine dimers (in cis-syn configuration), which are formed between adjacent bases on the same DNA strand upon exposure to ultraviolet radiation. 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 PubMedPhotolyase repairs ultraviolet (UV) damage to DNA by splitting the cyclobutane ring of the major UV photoproduct, the cis, syn-cyclobutane pyrimidine dimer (Pyr <> Pyr). The reaction is initiated by blue light and proceeds through long-range energy transfer, single electron transfer, and enzyme catalysis by a radical mechanism. The three-dimensional crystallographic structure of DNA photolyase from Escherichia coli is presented and the atomic model was refined to an R value of 0.172 at 2.3 A resolution. The polypeptide chain of 471 amino acids is folded into an amino-terminal alpha/beta domain resembling dinucleotide binding domains and a carboxyl-terminal helical domain; a loop of 72 residues connects the domains. The light-harvesting cofactor 5,10-methenyltetrahydrofolylpolyglutamate (MTHF) binds in a cleft between the two domains. Energy transfer from MTHF to the catalytic cofactor flavin adenine dinucleotide (FAD) occurs over a distance of 16.8 A. The FAD adopts a U-shaped conformation between two helix clusters in the center of the helical domain and is accessible through a hole in the surface of this domain. Dimensions and polarity of the hole match those of a Pyr <> Pyr dinucleotide, suggesting that the Pyr <> Pyr "flips out" of the helix to fit into this hole, and that electron transfer between the flavin and the Pyr <> Pyr occurs over van der Waals contact distance. Crystal structure of DNA photolyase from Escherichia coli.,Park HW, Kim ST, Sancar A, Deisenhofer J Science. 1995 Jun 30;268(5219):1866-72. PMID:7604260[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
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