36 research outputs found
DFT-based Conformational Analysis of a Phospholipid Molecule (DMPC)
The conformational space of the dimyristoyl phosphatidylcholine (DMPC)
molecule has been studied using Density Functional Theory (DFT), augmented with
a damped empirical dispersion energy term (DFT-D). Fourteen ground-state
isomers have been found with total energies within less than 1 kcal/mol.
Despite differences in combinations of their torsion angles, all these
conformers share a common geometric profile, which includes a balance of
attractive, repulsive and constraint forces between and within specific groups
of atoms. The definition of this profile fits with most of the structural
characteristics deduced from measured NMR properties of DMPC solutions. The
calculated vibrational spectrum of the molecule is in good agreement with
experimental data obtained for DMPC bilayers. These results support the idea
that DMPC molecules preserve their individual molecular structures in the
various assemblies.Comment: 31 pages, 6 Tables, 4 Figure
Intron RNA editing is essential for splicing in plant mitochondria
Most plant mitochondria messenger RNAs (mRNAs) undergo editing through C-to-U conversions located mainly in exon sequences. However, some RNA editing events are found in non-coding regions at critical positions in the predicted secondary and tertiary structures of introns, suggesting that RNA editing could be important for splicing. Here, we studied the relationships between editing and splicing of the mRNA encoding the ribosomal protein S10 (rps10), which has a group II intron and five editing sites. Two of them, C2 and C3, predicted to stabilize the folded structure of the intron necessary for splicing, were studied by using rps10 mutants introduced into isolated potato mitochondria by electroporation. While mutations of C2 involved in EBS2/IBS2 interactions did not affect splicing, probably by the presence of an alternative EBS2′ region in domain I of the intron, the edition of site C3 turned out to be critical for rps10 mRNA splicing; only the edited (U) form of the transcript was processed. Interestingly, RNA editing was strongly reduced in transcripts from two different intronless genes, rps10 from potato and cox2 from wheat, suggesting that efficient RNA processing may require a close interaction of factors engaged in different maturation processes. This is the first report linking editing and splicing in conditions close to the in vivo situation
An in vitro system for the editing of ATP synthase subunit 9 mRNA using wheat mitochondrial extracts.
Studies on the effects of nuclear background and tissue specificity on RNA editing of the mitochondrial ATP synthase subunits α, 6 and 9 in fertile and cytoplasmic male-sterile (CMS) wheat
Significant lower VVH7-like immunoreactivity serum level in diabetic patients: Evidence for independence from metabolic control and three key enzymes in hemorphin metabolism, cathepsin D, ACE and DPP-IV
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