Structural diversity of the region encompassing DIS, SD and Psi hairpins in HIV and SIV genomes.

We investigated in silico the secondary structure of the region encompassing DIS, SD and Psi hairpins in HIV-1 genomes of rare groups N, O and P, HIV-2 genomes and SIV genomes from chimpanzees, gorillas and monkeys. We found that the structure of this region in SIVcpzptt genomes of the 1st and the 2nd clusters is similar to that in HIV-1 genomes of groups M and N, respectively. Further, the structure of the region encompassing DIS, SD and Psi hairpins is similar in HIV-1 genomes of groups O and P and SIVgor genomes.

Genome sequence analysis suggests coevolution of the DIS, SD, and Psi hairpins in HIV-1 genomes.

HIV-1 RNA dimerization is a critical step in viral life cycle. It is a prerequisite for genome packaging and plays an important role in reverse transcription and recombination. Dimerization is promoted by the DIS (dimerization initiation site) hairpin located in the 5' leader of HIV-1 genome.

Structural transitions in poly(A), poly(C), poly(U), and poly(G) and their possible biological roles.

The homopolynucleotide (homo-oligonucleotide) tracts function as regulatory elements at various stages of mRNAs life cycle. Numerous cellular proteins specifically bind to these tracts. Among them are the different poly(A)-binding proteins, poly(C)-binding proteins, multifunctional fragile X mental retardation protein which binds specifically both to poly(G) and poly(U) and others.

Characterization of natural and irradiated nails by means of the depolarization metrics.

Mueller polarimetry is applied to study the samples of nails: natural (or reference) and irradiated to 2 Gy ionizing radiation dose. We measure the whole Mueller matrices of the samples as a function of the scattering angle at a wavelength of 632.8 nm.

Structural insight into HIV-1 reverse transcription initiation in MAL-like templates (CRF01_AE, subtype G and CRF02_AG).

Based on the known structural model for reverse transcription initiation complex of the human immunodeficiency virus type 1 (HIV-1) MAL isolate, we attempted to predict a structural behavior of MAL-like templates (CRF01_AE, subtype G and CRF02_AG) within the initiation complex by in silico experiments. Switches from the D-duplex (dimerization-competent) conformation to the I-duplex (initiation-competent) conformation and then to conformations with an open primer activation signal (PAS) structure have been examined for four fragments of U5 and primer binding site (PBS) region, the minimal fragment (nt 121-243), fragment 1 (nt 110-243), fragment 2 (nt 113-259), and extended fragment 2 (nt 109-261). Switches from the D-duplex conformation to the I-duplex conformation in the minimal fragment or fragment 1 and from the I-duplex conformation to conformations with exposed PAS motif in fragment 1 are similar in all MAL-like templates.