21 research outputs found
HIGH RESOLUTION INFRARED STUDY OF THE AND PERPENDICULAR BANDS OF
1. F. Megvellati, G. Graner, H. Bürger, K. Burczyk. H. S. P. Matter, and H. Willner J. Mol. Spectrosc. 164, 368 (1994)Author Institution: "CNRS, associé aux Universités P. et M. Curie et Paris-Sub", Bât 350. Campus d'Orsay, 91405 Orsay, France.; Universität Gesamthochschule, FB9, 42097 Wuppertal, Germany.; J. Heyrovsky Institute of Physical Chemistry, Dolejskova 3, 18223 Praha 8. Czech Republic.The IR spectra of isotopiclly pure samples of the two molecules and have been recorded with a Bruker 120 HR Fourier transform spectrometer at a resolution of . The two perpendicular fundamentals and localed at and for and 562.24615 (5) and for have been analyzed in detail, Ground statc consunts, up to the H's, have been fixed to values obtained in a previous . J and K values up to 98 and 84 respectively have been reached. The spectrum of is dominated by a resonance affecting almost all levels. This yields accurate values of the and molecular constants. We shall report for these four bands a set of upper state spectroscopic constants, which allows us to reproduce the experimental data with a standard deviation of on residuals
Eukaryotic GPN-loop GTPases paralogs use a dimeric assembly reminiscent of archeal GPN
GTPases are molecular switches that regulate a wide-range of cellular processes. The GPN-loop GTPase (GPN) is a sub-family of P-loop NTPase that evolved from a single gene copy in archaea to triplicate paralog genes in eukaryotes, each having a non-redundant essential function in cell. In Saccharomyces cerevisiae, yGPN1 and yGPN2 are involved in sister chromatid cohesion mechanism, whereas nothing is known regarding yGPN3 function. Previous high-throughput experiments suggested that GPN paralogs interaction may occur. In this work, GPN|GPN contact was analyzed in details using TAP-Tag approach, yeast two-hybrid assay, in silico energy computation and site-directed mutagenesis of a conserved Glu residue located at the center of the interaction interface. It is demonstrated that this residue is essential for cell viability. A chromatid cohesion assay revealed that, like yGPN1 and yGPN2, yGPN3 also plays a role in sister chromatid cohesion. These results suggest that all three GPN proteins act at the molecular level in sister chromatid cohesion mechanism as a GPN|GPN complex reminiscent of the homodimeric structure of PAB0955, an archaeal member of GPN-loop GTPase