HIGH RESOLUTION INFRARED STUDY OF THE v5v_{5} AND v6v_{6} PERPENDICULAR BANDS OF FCℓ18O3FC\ell^{18}O_{3}

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 $F^{35}C\ell^{18}O_{3}$ and $F^{37}C\ell^{18}O_{3}$ have been recorded with a Bruker 120 HR Fourier transform spectrometer at a resolution of ${\sim} 0.003 cm^{-1}$. The two perpendicular fundamentals $v_{5}$ and $v_{6}$ localed at $565.10234 (4)$ and $390.54017 (3) cm^{-1}$ for $F^{35}C\ell^{18}O_{3}$ and 562.24615 (5) and $390.49788 (3) cm^{-1}$ for $F^{37}C\ell^{18}O_{3}$ have been analyzed in detail, Ground statc consunts, up to the H's, have been fixed to values obtained in a previous $work^{1}$. J and K values up to 98 and 84 respectively have been reached. The spectrum of $v_{5}$ is dominated by a $\Delta K = \pm 3$ resonance affecting almost all levels. This yields accurate values of the $A_{o}$ and $D^{0}_{K}$ 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 $0.0003 cm^{-1}$ 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