Ribonucleoprotein RNP

Mechanistic studies of RNA enzymes (ribozymes) and ribonucleoprotein (RNP) complexes such as the ribosome and telomerase, often seek to characterize RNA structural features, either dynamic or static, and relate these properties to specific catalytic functions. Many experimental techniques that probe RNA structure-function relationships rely upon site-specific incorporation of chemically modified ribonucleotides into the RNA of interest, often in the form of chemical cross-linkers to probe for sites of protein-RNA interaction or small organic fluorophores to measure dynamic structural properties of RNAs. The ability to arbitrarily modify any RNA molecule has been greatly enabled by modern RNA synthesis techniques however, there remains a practical size... 

Anti-Ro/SSA antibody was identified in the serum of more than 10% of patients with connective tissue disease (CTD) (B20), making these autoantibodies the most prevalent of antibodies to ribonucleoprotein (RNP) antigens. The molecular weight of the major antigenic peptide is about 60 kDa (Yl). Other peptides related to anti-Ro autoantibodies include 52-kDa Ro, 54-kDa Ro, a second 60-kDa Ro, 57-kDa Ro, and calreticulin. There are four Ro-associated RNAs, hYl, hY3, hY4, and hY5, with length ranging from 84 to 112 bases. All four have been sequenced (K3, W14, Ol). 

High titres of anti-ribonucleoprotein (RNP), detected using an ELISA, are present in patients with features of mixed connective tissue disease. 

Lapinaite and colleagues have published a particularly impressive study of the box C/D ribonucleoprotein (RNP) from the archaeon Pyrococcus furiosus, a complex of 390 kDa responsible for methylating ribosomal RNA. ° By I, L, V-methyl labelling the three protein components of the complex, methyl TROSY spectra were used to monitor chemical shifts and PREs. Models for the entire complex could thus be calculated both with and without substrate RNA present using previously-determined structures of protein and RNA sub-units. Domain boundaries were allowed to be flexible during docking using NMR and SANS data, with... 

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