Showing papers by "Jose A. Gavira published in 2013"
TL;DR: Results support the notions that Precambrian life was thermophilic and that proteins can evolve from substrate-promiscuous generalists into specialists during the course of natural evolution and highlight the biotechnological potential of laboratory resurrection of Precambrians proteins.
Abstract: We report a sequence reconstruction analysis targeting several Precambrian nodes in the evolution of class-A β-lactamases and the preparation and experimental characterization of their encoded prot...
221 citations
TL;DR: X-ray crystal structures of seven laboratory resurrections of Precambrian thioredoxins dating up to approximately four billion years ago show a remarkable degree of structure conservation, which supports a punctuated-equilibrium model of structure evolution in which the generation of new folds occurs over comparatively short periods and is followed by long periods of structural stasis.
116 citations
TL;DR: In this article, the protein crystal lattice incorporates silica fibers during their growth, making the crystal appear optically translucent while maintaining the diffraction quality, and the effect of the silica fibres on the nucleation and growth morphology is discussed.
Abstract: Protein crystals were obtained in a wide range of silica gel concentrations, 2.0–22.0% (v/v), using the counter-diffusion technique. The protein crystal lattice incorporates silica fibers during their growth, making the crystal appear optically translucent while maintaining the diffraction quality. The effect of the silica fibers on the nucleation and growth morphology is discussed, and the amount of incorporated silica matrix is quantified. The practical implications of the presence of a high hygroscope phase on the crystal properties are discusse, and the improvement of the mechanical properties and stability of the crystals is shown. These reinforced protein crystals, able to include large amounts of silica, open a new range of possibilities for the characterization of protein crystals and the application in the biotechnological industry.
25 citations
TL;DR: In this article, the authors showed that heterogeneous agents are able to reduce required starting protein concentration and induction time for crystallization, but in many cases, the molecular mechani...
Abstract: Several studies have shown that heterogeneous agents are able to reduce required starting protein concentration and induction time for crystallization. However, in many cases, the molecular mechani...
21 citations
TL;DR: The paralogous chemoreceptors PctA and PctB (Pseudomonas chemotactic transducer A and B) were found to mediate chemotaxis towards L-amino acids, however, the ligand spectrum of the receptors is quite different since the recombinant ligand-binding region (LBR) of PptA binds 17 different L-Amino acids whereas that of PCTB recognizes only five.
Abstract: Pseudomonas aeruginosa is an opportunistic pathogen and one of the major model organisms for the study of chemotaxis. The bacterium harbours 26 genes encoding chemoreceptors, most of which have not been annotated with a function. The paralogous chemoreceptors PctA and PctB (Pseudomonas chemotactic transducer A and B) were found to mediate chemotaxis towards l-amino acids. However, the ligand spectrum of the receptors is quite different since the recombinant ligand-binding region (LBR) of PctA binds 17 different l-amino acids whereas that of PctB recognizes only five. To determine the molecular basis underlying this ligand specificity, PctA-LBR and PctB-LBR have been purified and crystals have been produced after pre-incubation with l-Ile and l-Arg, respectively. Initial crystallization conditions have been identified by the counter-diffusion method and X-ray data have been collected at 2.5 A (PctA-LBR bound to l-Ile) and 3.14 A (PctB-LBR bound to l-Arg) resolution. Crystals belonged to space groups P212121 and P3121, with unit-cell parameters a = 72.2, b = 78.5, c = 116.6 A and a = b = 111.6, c = 117.4, respectively, for PctA-LBR and PctB-LBR. Molecular-replacement methods will be pursued for structural determination.
3 citations
1 citations