저작근 근전도에 관한 정상교합자와 ii급 부정교합자의 비교 연구

Hypertension 66 (20.3%) 24 (24.2%) 30 (16.3%) NS Diabetes 20 (6.2%) 7 (7.1%) 10 (5.4%) NS Excess weight 78 (24%) 27 (27.3%) 44 (23.9%) NS Smokers 64 (19.7%) 17 (17.2%) 35 (19.0%) NS Age >50 years 137 (42.2%) 54 (54.5%) 67 (36.4%) <0.02 Kidney disease 7 (2.2%) 1 (1%) 5 (2.7%) NS Family history, DM 102 (31.4%) 28 (28.3%) 66 (35.9%) NS

Conflict of interest statement. None declared.

SUMMARY Small RNA regulators (sRNAs) have been identified in a wide range of bacteria and found to playcriticalregulatoryrolesinmanyprocesses.ThemajorfamiliesofsRNAsincludetrueantisense RNAs, synthesized from the strand complementary to the mRNA they regulate, sRNAs that also act by pairing but have limited complementarity with their targets, and sRNAs that regulate proteins by binding to and affecting protein activity. The sRNAs with limited complementarityare akin to eukaryotic microRNAs in theirability to modulate the activityand stability of multiple mRNAs. In many bacterial species, the RNA chaperone Hfq is required to promote pairing between these sRNAs and their target mRNAs. Understanding the evolution of regulatory sRNAs remains a challenge; sRNA genes show evidence of duplication and horizontal transfer but also could be evolved from tRNAs, mRNAs or random transcription.

/pdf/bacterial-small-rna-regulators-versatile-roles-and-rapidly-4e5izhexz6.pdf

Bacterial Small RNA Regulators: Versatile Roles and Rapidly Evolving Variations

Over the past two decades, nuclear magnetic resonance (NMR) has emerged as one of the three principal analytical techniques used in metabolomics (the other two being gas chromatography coupled to mass spectrometry (GC-MS) and liquid chromatography coupled with single-stage mass spectrometry (LC-MS)). The relative ease of sample preparation, the ability to quantify metabolite levels, the high level of experimental reproducibility, and the inherently nondestructive nature of NMR spectroscopy have made it the preferred platform for long-term or large-scale clinical metabolomic studies. These advantages, however, are often outweighed by the fact that most other analytical techniques, including both LC-MS and GC-MS, are inherently more sensitive than NMR, with lower limits of detection typically being 10 to 100 times better. This review is intended to introduce readers to the field of NMR-based metabolomics and to highlight both the advantages and disadvantages of NMR spectroscopy for metabolomic studies. It will also explore some of the unique strengths of NMR-based metabolomics, particularly with regard to isotope selection/detection, mixture deconvolution via 2D spectroscopy, automation, and the ability to noninvasively analyze native tissue specimens. Finally, this review will highlight a number of emerging NMR techniques and technologies that are being used to strengthen its utility and overcome its inherent limitations in metabolomic applications.

/pdf/nmr-spectroscopy-for-metabolomics-research-44r60kdl08.pdf

NMR Spectroscopy for Metabolomics Research.

Summary In many g-proteobacteria, the conserved GacS/GacA (BarA/UvrY) two-component system positively con- trols the expression of one to five genes specifying small RNAs (sRNAs) that are characterized by repeated unpaired GGA motifs but otherwise appear to belong to several independent families. The GGA motifs are essential for binding small, dimeric RNA- binding proteins of a single conserved family desig- nated RsmA (CsrA). These proteins, which also occur in bacterial species outside the g-proteobacteria, act as translational repressors of certain mRNAs when these contain an RsmA/CsrA binding site at or near the Shine-Dalgarno sequence plus additional binding sites located in the 5 untranslated leader mRNA. Recent structural data have established that the RsmA-like protein RsmE of Pseudomonas fluore- scens makes specific contacts with an RNA consen- sus sequence 5- A /UCANGGANG U /A-3 (where N is any nucleotide). Interaction with an RsmA/CsrA protein promotes the formation of a short stem supporting an ANGGAN loop. This conformation hinders access of 30S ribosomal subunits and hence translation initiation. The output of the Gac/Rsm cascade varies widely in different bacterial species and typically involves management of carbon storage and expres- sion of virulence or biocontrol factors. Unidentified signal molecules co-ordinate the activity of the Gac/ Rsm cascade in a cell population density-dependent manner.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2958.2007.06042.x

Gac/Rsm signal transduction pathway of γ‐proteobacteria: from RNA recognition to regulation of social behaviour

Proteins of the RsmA/CsrA family are global translational regulators in many bacterial species. We have determined the solution structure of a complex formed between the RsmE protein, a member of this family from Pseudomonas fluorescens, and a target RNA encompassing the ribosome-binding site of the hcnA gene. The RsmE homodimer with its two RNA-binding sites makes optimal contact with an 5'-A/UCANGGANGU/A-3' sequence in the mRNA. When tightly gripped by RsmE, the ANGGAN core folds into a loop, favoring the formation of a 3-base-pair stem by flanking nucleotides. We validated these findings by in vivo and in vitro mutational analyses. The structure of the complex explains well how, by sequestering the Shine-Dalgarno sequence, the RsmA/CsrA proteins repress translation.

/pdf/molecular-basis-of-messenger-rna-recognition-by-the-specific-3mjnbrsq7f.pdf

Molecular basis of messenger RNA recognition by the specific bacterial repressing clamp RsmA/CsrA

MicroRNA and protein sequestration by non-coding RNAs (ncRNAs) has recently generated much interest. In the bacterial Csr/Rsm system, which is considered to be the most general global post-transcriptional regulatory system responsible for bacterial virulence, ncRNAs such as CsrB or RsmZ activate translation initiation by sequestering homodimeric CsrA-type proteins from the ribosome-binding site of a subset of messenger RNAs. However, the mechanism of ncRNA-mediated protein sequestration is not understood at the molecular level. Here we show for Pseudomonas fluorescens that RsmE protein dimers assemble sequentially, specifically and cooperatively onto the ncRNA RsmZ within a narrow affinity range. This assembly yields two different native ribonucleoprotein structures. Using a powerful combination of nuclear magnetic resonance and electron paramagnetic resonance spectroscopy we elucidate these 70-kilodalton solution structures, thereby revealing the molecular mechanism of the sequestration process and how RsmE binding protects the ncRNA from RNase E degradation. Overall, our findings suggest that RsmZ is well-tuned to sequester, store and release RsmE and therefore can be viewed as an ideal protein 'sponge'.

Structural basis of the non-coding RNA RsmZ acting as a protein sponge

High-resolution structural information on RNA and its functionally important complexes with proteins is dramatically underrepresented compared with proteins but is urgently needed for understanding cellular processes at the molecular and atomic level. Here we present an EPR-based protocol to help solving large RNA and protein-RNA complex structures in solution by providing long-range distance constraints between rigid fragments. Using enzymatic ligation of smaller RNA fragments, large doubly spin-labelled RNAs can be obtained permitting the acquisition of long distance distributions (>80 A) within a large protein-RNA complex. Using a simple and fast calculation in torsion angle space of the spin-label distributions with the program CYANA, we can derive simple distance constraints between the spin labels and use them together with short-range distance restraints derived from NMR to determine the structure of a 70 kDa protein-RNA complex composed of three subcomplexes.

/pdf/epr-aided-approach-for-solution-structure-determination-of-109kr3t3o8.pdf

EPR-aided approach for solution structure determination of large RNAs or protein–RNA complexes

Structure determination and dynamics of protein-RNA complexes by NMR spectroscopy.

Structural information on RNA, emerging more and more as a major regulator in gene expression, dramatically lags behind compared with information on proteins. Although NMR spectroscopy has proven to be an excellent tool to solve RNA structures, it is hampered by the severe spectral resonances overlap found in RNA, limiting its use for large RNA molecules. Segmental isotope labeling of RNA or ligation of a chemically synthesized RNA containing modified nucleotides with an unmodified RNA fragment have proven to have high potential in overcoming current limitations in obtaining structural information on RNA. However, low yields, cumbersome preparations and sequence requirements have limited its broader application in structural biology. Here we present a fast and efficient approach to generate multiple segmentally labeled RNAs with virtually no sequence requirements with very high yields (up to 10-fold higher than previously reported). We expect this approach to open new avenues in structural biology of RNA.

/pdf/a-fast-efficient-and-sequence-independent-method-for-1iw2isar6f.pdf

Olivier Duss

Papers

Molecular basis of messenger RNA recognition by the specific bacterial repressing clamp RsmA/CsrA

Structural basis of the non-coding RNA RsmZ acting as a protein sponge

EPR-aided approach for solution structure determination of large RNAs or protein–RNA complexes

Structure determination and dynamics of protein-RNA complexes by NMR spectroscopy.

A fast, efficient and sequence-independent method for flexible multiple segmental isotope labeling of RNA using ribozyme and RNase H cleavage