3-[2-(1,3-Benzothia­zol-2-ylsulfan­yl)eth­yl]-1,3-oxazolidin-2-one

The title compound, C12H12N2S2O2, consists of a benzothia­zole group and a oxazolidin-1-one linked via a flexible ethane-1,2-diyl spacer. The benzothiazole group and the oxazolidine ring are each almost planar [with maximum deviations of 0.007 (2) and 0.044 (3) Å, respectively] and make a dihedral angle of 9.35 (10)°. In the crystal structure, adjacent mol­ecules were connected through C—H⋯O and C—H⋯N hydrogen bonds, and further extended into a three-dimensional network structure through inter­molecular aromatic π–π stacking inter­actions in which the centroid–centroid distance is 3.590 (1) Å

Crystal structures of adenylylated and unadenylylated P II protein GlnK from Corynebacterium glutamicum

PII proteins are ubiquitous signaling proteins that are involved in the regulation of the nitrogen carbon balance in bacteria, archaea, and some plants and algae. Signal transduction via PII proteins is modulated by effector molecules and post translational modifications in the PII T loop. Whereas the binding of ADP, ATP and the concomitant binding of ATP and 2 oxoglutarate 2OG engender two distinct conformations of the T loop that either favor or disfavor the interaction with partner proteins, the structural consequences of post translational modifications such as phosphorylation, uridylylation and adenylylation are far less well understood. In the present study, crystal structures of the PII protein GlnK from Corynebacterium glutamicum have been determined, namely of adenylylated GlnK adGlnK and unmodified unadenylylated GlnK unGlnK . AdGlnK has been proposed to act as an inducer of the transcription repressor AmtR, and the adenylylation of Tyr51 in GlnK has been proposed to be a prerequisite for this function. The structures of unGlnK and adGlnK allow the first atomic insights into the structural implications of the covalent attachment of an AMP moiety to the T loop. The overall GlnK fold remains unaltered upon adenylylation, and T loop adenylylation does not appear to interfere with the formation of the two major functionally important T loop conformations, namely the extended T loop in the canonical ADP bound state and the compacted T loop that is adopted upon the simultaneous binding of Mg ATP and 2OG. Thus, the PII typical conformational switching mechanism appears to be preserved in GlnK from C. glutamicum, while at the same time the functional repertoire becomes expanded through the accommodation of a peculiar post translational modificatio

Chemically modified exopolysaccharide pullulans: physico-chemical characteristics of ionic derivatives

International audienceThe paper presents some physico-chemical characteristics of dilute solutions of exopolysaccharide pullulan and its carboxymethyl, sulfoethyl and sulfopropyl ionic derivatives.On-line size exclusion chromatography/multi-angle laser light scattering (SEC/ MALLS) was used for establishing their weight average molecular weight (Mw), number average molecular weight (Mn), polydispersity index (Ip = Mw/Mn) and radius of gyration Rg

Measurement of the K-L ->pi mu nu form factor parameters with the KLOE detector

Using 328 pb(-1) of data collected at DA phi NE corresponding to similar to 1.8 million K-L -> pi mu nu decays, we have measured the K-mu 3 form factor parameters. The structure of the K-pi vector-current provides information about the dynamics of the strong interaction; its knowledge is necessary for evaluation of the phase-space integral required for measuring the CKM matrix element V-us and for testing lepton universality in kaon decays. Using a new parametrization for the vector and scalar form factors, we find lambda(+)=(25.7 +/- 0.6) x 10(-3) and lambda(0) = (14.0 +/- 2.1) x 10(-3). Our result for lambda(0), together with recent lattice calculations of f pi, fK and f(0), satisfies the Callan-Treiman relation