@article {2018, title = {RecA requires two molecules of Mg2+ ions for its optimal strand exchange activity in vitro}, journal = {Nucleic Acids Res}, volume = {ahead of print}, year = {2018}, month = {Jan}, abstract = {

Mg2+ ion stimulates the DNA strand exchange reaction catalyzed by RecA, a key step in homologous recombination. To elucidate the molecular mechanisms underlying the role of Mg2+ and the strand exchange reaction itself, we investigated the interaction of RecA with Mg2+ and sought to determine which step of the reaction is affected. Thermal stability, intrinsic fluorescence, and native mass spectrometric analyses of RecA revealed that RecA binds at least two Mg2+ ions with KD \‚{\^a}{\`a} 2 mM and 5 mM. Deletion of the C-terminal acidic tail of RecA made its thermal stability and fluorescence characteristics insensitive to Mg2+ and similar to those of full-length RecA in the presence of saturating Mg2+. These observations, together with the results of a molecular dynamics simulation, support the idea that the acidic tail hampers the strand exchange reaction by interacting with other parts of RecA, and that binding of Mg2+ to the tail prevents these interactions and releases RecA from inhibition. We observed that binding of the first Mg2+ stimulated joint molecule formation, whereas binding of the second stimulated progression of the reaction. Thus, RecA is actively involved in the strand exchange step as well as bringing the two DNAs close to each other.

}, doi = {10.1093/nar/gky048}, author = {Kim, Raeyeong and Kanamaru, Shuji and Mikawa, Tsutomu and Chantal Pr{\'e}vost and Ishii, Kentaro and Ito, Kentaro and Uchiyama, Susumu and Oda, Masayuki and Iwasaki, Hiroshi and Kim, Seog K and Takahashi, Masayuki} } @article {2015|1664, title = {Membrane Protein Structure, Function, and Dynamics: a Perspective from Experiments and Theory.}, journal = {J. Membr. Biol.}, volume = {248}, year = {2015}, publisher = {Biomedical Research Foundation, Academy of Athens, 4 Soranou Ephessiou, 11527, Athens, Greece, zcournia@bioacademy.gr.}, chapter = {611}, abstract = {

Membrane proteins mediate processes that are fundamental for the flourishing of biological cells. Membrane-embedded transporters move ions and larger solutes across membranes; receptors mediate communication between the cell and its environment and membrane-embedded enzymes catalyze chemical reactions. Understanding these mechanisms of action requires knowledge of how the proteins couple to their fluid, hydrated lipid membrane environment. We present here current studies in computational and experimental membrane protein biophysics, and show how they address outstanding challenges in understanding the complex environmental effects on the structure, function, and dynamics of membrane proteins.

}, doi = {10.1007/s00232-015-9802-0}, author = {Cournia, Zoe and Allen, Toby W. and Andricioaei, Ioan and Antonny, Bruno and Baum, Daniel and Grace Brannigan and Buchete, Nicolae-Viorel and Deckman, Jason T. and Delemotte, Lucie and Del Val, Coral and Friedman, Ran and Gkeka, Paraskevi and Hege, Hans-Christian and J{\'e}r{\^o}me H{\'e}nin and Kasimova, Marina A. and Kolocouris, Antonios and Michael L Klein and Khalid, Syma and Lemieux, M Joanne and Lindow, Norbert and Roy, Mahua and Selent, Jana and Mounir Tarek and Tofoleanu, Florentina and Vanni, Stefano and Urban, Sinisa and Wales, David J. and Smith, Jeremy C. and Bondar, Ana-Nicoleta} } @article {2014|1931, title = {Assessing the effect of dynamics on the closed-loop protein-folding hypothesis}, journal = {Journal of the Royal Society Interface}, volume = {11}, number = {91}, year = {2014}, pages = {20130935}, doi = {10.1098/rsif.2013.0935}, url = {http://rsif.royalsocietypublishing.org/content/11/91/20130935.abstract}, author = {Chintapalli, Sree V. and Illingworth, Christopher J. R. and Upton, Graham J. G. and S Sacquin-Mora and Reeves, Philip J. and Mohammedali, Hani S. and Reynolds, Christopher A.} } @article {2011|1665, title = {Community-wide assessment of protein-interface modeling suggests improvements to design methodology.}, journal = {J. Mol. Biol.}, volume = {414}, year = {2011}, month = {nov}, pages = {289{\textendash}302}, abstract = {

The CAPRI (Critical Assessment of Predicted Interactions) and CASP (Critical Assessment of protein Structure Prediction) experiments have demonstrated the power of community-wide tests of methodology in assessing the current state of the art and spurring progress in the very challenging areas of protein docking and structure prediction. We sought to bring the power of community-wide experiments to bear on a very challenging protein design problem that provides a complementary but equally fundamental test of current understanding of protein-binding thermodynamics. We have generated a number of designed protein-protein interfaces with very favorable computed binding energies but which do not appear to be formed in experiments, suggesting that there may be important physical chemistry missing in the energy calculations. A total of 28 research groups took up the challenge of determining what is missing: we provided structures of 87 designed complexes and 120 naturally occurring complexes and asked participants to identify energetic contributions and/or structural features that distinguish between the two sets. The community found that electrostatics and solvation terms partially distinguish the designs from the natural complexes, largely due to the nonpolar character of the designed interactions. Beyond this polarity difference, the community found that the designed binding surfaces were, on average, structurally less embedded in the designed monomers, suggesting that backbone conformational rigidity at the designed surface is important for realization of the designed function. These results can be used to improve computational design strategies, but there is still much to be learned; for example, one designed complex, which does form in experiments, was classified by all metrics as a nonbinder.

}, keywords = {Binding Sites, Models, Molecular, Protein Binding, Proteins}, issn = {1089-8638}, doi = {10.1016/j.jmb.2011.09.031}, author = {Fleishman, Sarel J and Whitehead, Timothy A and Strauch, Eva-Maria and Corn, Jacob E and Qin, Sanbo and Zhou, Huan-Xiang and Mitchell, Julie C and Demerdash, Omar N A and Takeda-Shitaka, Mayuko and Terashi, Genki and Moal, Iain H and Li, Xiaofan and Bates, Paul A and Martin Zacharias and Park, Hahnbeom and Ko, Jun-su and Lee, Hasup and Seok, Chaok and Bourquard, Thomas and Bernauer, Julie and Poupon, Anne and Az{\'e}, J{\'e}r{\^o}me and Soner, Seren and Ovali, Sefik Kerem and Ozbek, Pemra and Tal, Nir Ben and Haliloglu, T{\"u}rkan and Hwang, Howook and Vreven, Thom and Pierce, Brian G and Weng, Zhiping and P{\'e}rez-Cano, Laura and Pons, Carles and Fern{\'a}ndez-Recio, Juan and Jiang, Fan and Yang, Feng and Gong, Xinqi and Cao, Libin and Xu, Xianjin and Liu, Bin and Wang, Panwen and Li, Chunhua and Wang, Cunxin and Charles H. Robert and Guharoy, Mainak and Liu, Shiyong and Huang, Yangyu and Li, Lin and Guo, Dachuan and Chen, Ying and Xiao, Yi and London, Nir and Itzhaki, Zohar and Schueler-Furman, Ora and Inbar, Yuval and Potapov, Vladimir and Cohen, Mati and Schreiber, Gideon and Tsuchiya, Yuko and Kanamori, Eiji and Standley, Daron M and Nakamura, Haruki and Kinoshita, Kengo and Driggers, Camden M and Hall, Robert G and Morgan, Jessica L and Hsu, Victor L and Zhan, Jian and Yang, Yuedong and Zhou, Yaoqi and Kastritis, Panagiotis L and Bonvin, Alexandre M J J and Zhang, Weiyi and Camacho, Carlos J and Kilambi, Krishna P and Sircar, Aroop and Gray, Jeffrey J and Ohue, Masahito and Uchikoga, Nobuyuki and Matsuzaki, Yuri and Ishida, Takashi and Akiyama, Yutaka and Khashan, Raed and Bush, Stephen and Fouches, Denis and Tropsha, Alexander and Esquivel-Rodr{\'\i}guez, Juan and Kihara, Daisuke and Stranges, P Benjamin and Jacak, Ron and Kuhlman, Brian and Huang, Sheng-You and Zou, Xiaoqin and Wodak, Shoshana J and Janin, Jo{\"e}l and Baker, David} } @article {2009|1394, title = {Disulfide bond substitution by directed evolution in an engineered binding-protein scaffold.}, journal = {Chembiochem}, volume = {10}, year = {2009}, pages = {1349{\textendash}1359}, author = {Antoine Drevelle and Agathe Urvoas and M{\'e}riam Ben Hamida-Rebai and G{\'e}rard Van Vooren and Magali Nicaise and Marie Valerio-Lepiniec and Michel Desmadril and Charles H. Robert and Philippe Minard} } @inbook {2004|1730, title = {Conformational transitions in proteins and membranes}, booktitle = {Novel Approaches to the Structure and Dynamics of Liquids: Experiments, Theories and Simulations}, year = {2004}, pages = {485{\textendash}502}, publisher = {Springer Netherlands}, organization = {Springer Netherlands}, author = {Smith, Jeremy C and Cournia, Zoe and Antoine Taly and Tournier, Alexander L and Mihailescu, Dan and Ullmann, G Matthias} } @article {2003|1621, title = {The position of Q B in the photosynthetic reaction center depends on pH: A theoretical analysis of the proton uptake upon Q B reduction}, journal = {Biophys. J.}, volume = {84}, number = {3}, year = {2003}, pages = {2090{\textendash}2098}, publisher = {Cell Press}, author = {Antoine Taly and Sebban, Pierre and Smith, Jeremy C and Ullmann, G Matthias} }