RNA fold | ScienceGate

The ribosome is a ribozyme whose active site, the peptidyl transferase center (PTC), is situated within a highly conserved universal symmetrical region that connects all ribosomal functional centers involved in amino acid polymerization. The linkage between this elaborate architecture and A-site tRNA position revealed that the A-> P-site passage of the tRNA terminus in the peptidyl transferase center is performed by a rotatory motion, synchronized with the overall tRNA/mRNA sideways movement. Guided by the PTC, the rotatory motion leads to stereochemistry suitable for peptide bond formation, as well as for substrate-mediated catalysis, consistent with quantum mechanical calculations elucidating the transition state mechanism for peptide bond formation and indicating that the peptide bond is being formed during the rotatory motion. Analysis of substrate binding modes to inactive and active ribosomes illuminated the significant PTC mobility and supported the hypothesis that the ancient ribosome produced single peptide bonds and non-coded chains, utilizing free amino acids. Genetic control of the reaction evolved after poly-peptides capable of enzymatic function were created, and an ancient stable RNA fold was converted into tRNA molecules. As the symmetry relates only the backbone fold and nucleotide orientations, but not nucleotide sequence, it emphasizes the superiority of functional requirement over sequence conservation, and indicates that the PTC has evolved by gene fusion, presumably by taking advantage of similar RNA fold structures.

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A Common Variant of ASAP1 Is Associated with Tuberculosis Susceptibility in the Han Chinese Population

Disease Markers ◽

10.1155/2019/7945429 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Cheng Chen ◽

Qi Zhao ◽

Yan Shao ◽

Yan Li ◽

Honghuan Song ◽

...

Keyword(s):

Genetic Variant ◽

Peripheral Blood Monocyte ◽

Gtpase Activating Protein ◽

Potential Biomarker ◽

Significant Locus ◽

Latent Tb ◽

Hydrolysis Of ◽

Adp Ribosylation Factor ◽

Rna Fold

Background. ASAP1 (also known as AMAP1 or DDEF1) encodes an Arf GTPase-activating protein (Arf GAP), a multifunctional scaffold protein that induces hydrolysis of GTP bound to the ADP-ribosylation factor (Arf) family GTP-binding proteins. Reduction of ASAP1 expression in vitro was related to suppression of cell migration and invasiveness. The genetic variant rs4733781 of the ASAP1 gene was revealed as a significant locus for tuberculosis (TB) susceptibility, but the results still need to be validated. Methods. Blood samples from a total of 1914 active TB and healthy controls (HC) were collected to evaluate rs4733781 and the risk of TB. Meanwhile, a total of 48 noninfected HC, latent TB-infected (LTBI) controls, and active TB were collected to assay ASAP1 expression difference among the three groups. The QuantiFERON-TB Gold In-Tube was adopted to identify noninfected HC and LTBI. Results. The genetic variant of rs4733781 was found to be significantly associated with TB, and the A allele of rs4733781 (C>A) was 0.38 and 0.43 among TB cases and HC, respectively (P=0.0035). Meanwhile, the peripheral blood monocyte RNA fold changes for the ASAP1 gene among the 16 HC, 16 LTBI, and 16 active TB were 1.088±0.4919, 2.237±0.6505, and 10.12±10.98 (F=9.559, P=0.0003), respectively, and the expression of ASAP1 was increased by 2.06-fold (P<0.0001) and 9.30-fold (P<0.0052) for LTBI and active TB, when compared to the HC. Conclusions. Our data indicated that the A allele of rs4733781 for the ASAP1 gene was in association with a decreased risk of TB. But not only that, the overexpression of the ASAP1 gene among LTBI and TB was related to the progression of TB, which further implies that the expression of ASAP1 would be a potential biomarker for LTBI and TB diagnoses.

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Group I intron-like insertions in SSU rDNA of Cladonia gracilis and C. rangiferina

The Lichenologist ◽

10.1017/s0024282904014501 ◽

2004 ◽

Vol 36 (6) ◽

pp. 365-380 ◽

Cited By ~ 4

Author(s):

Michele D. PIERCEY-NORMORE ◽

Georg HAUSNER ◽

Ewan A. GIBB

Keyword(s):

Rna Structure ◽

Group I Intron ◽

Group I Introns ◽

16S Rdna Gene ◽

E Coli ◽

Group I ◽

History Of ◽

First Time ◽

Large Groups ◽

Rna Fold

During a study on population genetics of three species of Cladonia using the nuclear ribosomal 18S DNA, two species contained group I intron-like sequences located in positions 788 and 940 with reference to the E. coli 16S rDNA gene. The intron in position 940 was not typical of group I introns and had previously been described only from the Parmeliaceae and Lecanoraceae, but here we report the occurrence of this intron in the Cladoniaceae. The intron in position 788 had characteristics of group I introns and had previously been reported from the Physciaceae. In this paper we provide for the first time a putative RNA fold for the nS788 intron, compare the secondary RNA structure of the Cladonia group I introns (nS788 and nS940) to that of other taxa, and infer a phylogenetic history among 15 members of the Lecanorales based on the evolutionary history of the nS788 group I intron. The RNA fold for nS788 contained two optional hairpins, P2.1 and a potentially newly described hairpin referred to as P5.1. The phylogenetic hypothesis supports the monophyly of the genus Cladonia. It also supports the separation of two large groups in the Physciaceae; the Buellia-group and the Physcia-group.

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