Deciphering RNA G-quadruplex function during the early steps of HIV-1 infection.

G-quadruplexes (G4s) are four-stranded nucleic acid structures formed by the stacking of G-tetrads. Here we investigated their formation and function during HIV-1 infection. Using bioinformatics and biophysics analyses we first searched for evolutionary conserved G4-forming sequences in HIV-1 genome.

The bacterial communities of surface soils from desert sites in the eastern Utah (USA) portion of the Colorado Plateau.

Desert-like areas located in the eastern portion of the state of Utah (USA) have geographic features that can resemble the surface of the planet Mars, characterized by red-colored hills, soils and sandstones. We examined the bacterial biodiversity of surface soil samples from several sites from the Colorado Plateau Desert in eastern Utah using pyrosequencing of PCR amplified bacterial 16S rRNA genes from total extracted soil DNA. The sample sites cover the Great Basin, Goblin Valley State Park and nearby regions on the Colorado Plateau.

Author Correction: RNA synthesis is modulated by G-quadruplex formation in Hepatitis C virus negative RNA strand.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

RNA synthesis is modulated by G-quadruplex formation in Hepatitis C virus negative RNA strand.

DNA and RNA guanine-rich oligonucleotides can form non-canonical structures called G-quadruplexes or "G4" that are based on the stacking of G-quartets. The role of DNA and RNA G4 is documented in eukaryotic cells and in pathogens such as viruses. Yet, G4 have been identified only in a few RNA viruses, including the Flaviviridae family.

Hepatitis C virus intragenomic interactions are modulated by the SLVI RNA structure of the core coding sequence.

Several RNA interactions are thought to play a role in the regulation of the hepatitis C virus (HCV) life cycle. Most of these interactions involve the 5BSL3.2 domain and therefore occur at the 3' end of the viral genomic RNA.

Mutations of the SL2 dimerization sequence of the hepatitis C genome abrogate viral replication.

Stem-loop SL2 is a self-interacting palindromic sequence that has been identified within the hepatitis C virus genome (HCV). While, RNA dimerization of the HCV genome has been observed in vitro with short RNA sequences, the role of a putative RNA dimerization during viral replication has not been elucidated. To determine the effect of genomic dimerization on viral replication, we introduced mutations into SL2 predicted to disrupt genomic dimerization.