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Olmos, J.

Publications and source records attributed to Olmos, J..

2 recordsLinked to original sources

CRISPR/Cas9-based edition of frataxin gene in Dictyostelium discoideum for Friedreich's Ataxia disease modeling

In this paper we describe the development of a new model system for Friedreichs Atax- ia (FA) using Dictyostelium discoideum. We investigated the conservation of function between humans and D. discoideum and showed that DdFXN can substitute the human version in the interaction and activation of the Fe-S assembly supercomplex. We edited the fxn locus and isolated a defective mutant, clone 8, which presents landmarks of frataxin deficiency, such as a decrease in Fe-S cluster-dependent enzymatic functions, growth rate reduction, and increased sensitivity to oxidative stress. In addition multicellular development is affected as well as grow on bacterial lawn. We also assessed the rescuing capacity of DdFXN-G122V, a version that mimics a human variant present in some FA patients. While the expression of DdFXN-G122V rescues growth and enzymatic activity defects, as DdFXN does, multicellular development defects were only partially rescued The results of the study suggest that this new model system offers a wide range of pos- sibilities to easily explore diverse phenotypes in FA and develop drug or treatment screenings for designing and evaluating therapeutic strategies.

cell biology↗

Authentic Enzyme Intermediates Captured "on-the-fly" by Mix-and-Inject Serial Crystallography

Ever since the first atomic structure of an enzyme was solved, the discovery of the mechanism and dynamics of reactions catalyzed by biomolecules has been the key goal for the understanding of the molecular processes that drive life on earth. Despite a large number of successful methods for trapping reaction intermediates, the direct observation of an ongoing reaction has been possible only in rare and exceptional cases. Here, we demonstrate a general method for capturing enzyme catalysis in-action by mix-and-inject serial crystallography. Specifically, we follow the catalytic reaction of the Mycobacterium tuberculosis -lactamase with the 3rd generation antibiotic ceftriaxone by time-resolved serial femtosecond crystallography. The results reveal, in near atomic detail, antibiotic cleavage and inactivation on the millisecond to second time scales including the crossover from transition state kinetics to steady-state kinetics.\n\nSynopsisAn enzymatically catalyzed reaction is initiated by diffusion based mixing of substrate and followed at runtime by time-resolved serial crystallography using a free electron laser.

biophysics↗