title: Solution phase dynamics of the DNA repair enzyme spore photoproduct lyase as probed by H/D exchange.
abstract: Spore photoproduct lyase (SPL) catalyzes the repair of the UV lesion spore photoproduct (SP) in a reaction dependent on S-adenosyl-L-methionine (SAM). We have utilized H/D exchange to show that in the presence of SAM, a significant reduction in H/D exchange is observed upon binding SPTpT or undamaged oligonucleotide, indicating a shift of 20 or 10 amide protons, respectively, from a rapidly-exchangable state to a fully-protected conformation. In the absence of SAM, neither the oligonucleotide nor the SPTpT produce a significant perturbation in H/D exchange, indicating SAM is a requisite binding partner. Performing the same experiments in aerobic conditions reduced the magnitude of ligand-induced structural changes, consistent with the importance of the oxygen-sensitive iron-sulfur cluster for SAM and substrate binding.
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, United States.
authors.forename: Shourjo
authors.initials: S
authors.lastname: Ghose
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, United States.
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Hilmer
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, United States.
authors.forename: Brian
authors.initials: B
authors.lastname: Bothner
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, United States. Electronic address: jbroderick@chemistry.montana.edu.
authors.forename: Joan B
authors.initials: JB
authors.lastname: Broderick
mesh_terms: D046969:Clostridium acetobutylicum / Q000201:enzymology; D004260:DNA Repair; D041961:Deuterium Exchange Measurement; D008958:Models, Molecular; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D012436:S-Adenosylmethionine / Q000378:metabolism; D012996:Solutions
chemical_list: D011506:Proteins; D012996:Solutions; D012436:S-Adenosylmethionine; C088014:spore photoproduct lyase
keywords: DNA repair; H/D exchange; Mass spectrometry; Radical SAM