TY - JOUR A1 - Buechner, Claudia N. A1 - Maiti, Atanu A1 - Drohat, Alexander C. A1 - Tessmer, Ingrid T1 - Lesion search and recognition by thymine DNA glycosylase revealed by single molecule imaging JF - Nucleic Acids Research N2 - The ability of DNA glycosylases to rapidly and efficiently detect lesions among a vast excess of nondamaged DNA bases is vitally important in base excision repair (BER). Here, we use singlemolecule imaging by atomic force microscopy (AFM) supported by a 2-aminopurine fluorescence base flipping assay to study damage search by human thymine DNA glycosylase (hTDG), which initiates BER of mutagenic and cytotoxic G:T and G:U mispairs in DNA. Our data reveal an equilibrium between two conformational states of hTDG-DNA complexes, assigned as search complex (SC) and interrogation complex (IC), both at target lesions and undamaged DNA sites. Notably, for both hTDG and a second glycosylase, hOGG1, which recognizes structurally different 8-oxoguanine lesions, the conformation of the DNA in the SC mirrors innate structural properties of their respective target sites. In the IC, the DNA is sharply bent, as seen in crystal structures of hTDG lesion recognition complexes, which likely supports the base flipping required for lesion identification. Our results support a potentially general concept of sculpting of glycosylases to their targets, allowing them to exploit the energetic cost of DNA bending for initial lesion sensing, coupled with continuous (extrahelical) base interrogation during lesion search by DNA glycosylases. KW - Escherichia coli AlkA KW - undamaged DNA KW - substrate recognition KW - intrahelical lesion KW - uracil binding KW - structural basis KW - mismatch recognition KW - damaged DNA KW - base excision repair Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148795 VL - 43 IS - 5 ER - TY - JOUR A1 - Zaho, Huaying A1 - Ghirlando, Rodolfo A1 - Alfonso, Carlos A1 - Arisaka, Fumio A1 - Attali, Ilan A1 - Bain, David L. A1 - Bakhtina, Marina M. A1 - Becker, Donald F. A1 - Bedwell, Gregory J. A1 - Bekdemir, Ahmet A1 - Besong, Tabot M. D. A1 - Birck, Catherine A1 - Brautigam, Chad A. A1 - Brennerman, William A1 - Byron, Olwyn A1 - Bzowska, Agnieszka A1 - Chaires, Jonathan B. A1 - Chaton, Catherine T. A1 - Coelfen, Helmbut A1 - Connaghan, Keith D. A1 - Crowley, Kimberly A. A1 - Curth, Ute A1 - Daviter, Tina A1 - Dean, William L. A1 - Diez, Ana I. A1 - Ebel, Christine A1 - Eckert, Debra M. A1 - Eisele, Leslie E. A1 - Eisenstein, Edward A1 - England, Patrick A1 - Escalante, Carlos A1 - Fagan, Jeffrey A. A1 - Fairman, Robert A1 - Finn, Ron M. A1 - Fischle, Wolfgang A1 - Garcia de la Torre, Jose A1 - Gor, Jayesh A1 - Gustafsson, Henning A1 - Hall, Damien A1 - Harding, Stephen E. A1 - Hernandez Cifre, Jose G. A1 - Herr, Andrew B. A1 - Howell, Elizabeth E. A1 - Isaac, Richard S. A1 - Jao, Shu-Chuan A1 - Jose, Davis A1 - Kim, Soon-Jong A1 - Kokona, Bashkim A1 - Kornblatt, Jack A. A1 - Kosek, Dalibor A1 - Krayukhina, Elena A1 - Krzizike, Daniel A1 - Kusznir, Eric A. A1 - Kwon, Hyewon A1 - Larson, Adam A1 - Laue, Thomas M. A1 - Le Roy, Aline A1 - Leech, Andrew P. A1 - Lilie, Hauke A1 - Luger, Karolin A1 - Luque-Ortega, Juan R. A1 - Ma, Jia A1 - May, Carrie A. A1 - Maynard, Ernest L. A1 - Modrak-Wojcik, Anna A1 - Mok, Yee-Foong A1 - Mücke, Norbert A1 - Nagel-Steger, Luitgard A1 - Narlikar, Geeta J. A1 - Noda, Masanori A1 - Nourse, Amanda A1 - Obsil, Thomas A1 - Park, Chad K A1 - Park, Jin-Ku A1 - Pawelek, Peter D. A1 - Perdue, Erby E. A1 - Perkins, Stephen J. A1 - Perugini, Matthew A. A1 - Peterson, Craig L. A1 - Peverelli, Martin G. A1 - Piszczek, Grzegorz A1 - Prag, Gali A1 - Prevelige, Peter E. A1 - Raynal, Bertrand D. E. A1 - Rezabkova, Lenka A1 - Richter, Klaus A1 - Ringel, Alison E. A1 - Rosenberg, Rose A1 - Rowe, Arthur J. A1 - Rufer, Arne C. A1 - Scott, David J. A1 - Seravalli, Javier G. A1 - Solovyova, Alexandra S. A1 - Song, Renjie A1 - Staunton, David A1 - Stoddard, Caitlin A1 - Stott, Katherine A1 - Strauss, Holder M. A1 - Streicher, Werner W. A1 - Sumida, John P. A1 - Swygert, Sarah G. A1 - Szczepanowski, Roman H. A1 - Tessmer, Ingrid A1 - Toth, Ronald T. A1 - Tripathy, Ashutosh A1 - Uchiyama, Susumu A1 - Uebel, Stephan F. W. A1 - Unzai, Satoru A1 - Gruber, Anna Vitlin A1 - von Hippel, Peter H. A1 - Wandrey, Christine A1 - Wang, Szu-Huan A1 - Weitzel, Steven E A1 - Wielgus-Kutrowska, Beata A1 - Wolberger, Cynthia A1 - Wolff, Martin A1 - Wright, Edward A1 - Wu, Yu-Sung A1 - Wubben, Jacinta M. A1 - Schuck, Peter T1 - A Multilaboratory Comparison of Calibration Accuracy and the Performance of External References in Analytical Ultracentrifugation JF - PLoS ONE N2 - Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304\(\pm\)0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of \(\pm\)0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies. KW - fluorescence-detected sedimentation KW - size exclusion chromatography KW - field flow fractionation KW - spinco ultracentrifuge KW - aggregation KW - bead models KW - velocity KW - hydrodynamics KW - biopharmaceuticals KW - proteins Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151903 VL - 10 IS - 5 ER -