Human immunodeficiency virus, type 1 (HIV-1), Tat activates elongation of RNA polymerase II transcription at the HIV-1 promoter through interaction with the cyclin T1 (CycT1) subunit of the positive transcription elongation factor complex, P-TEFb. Binding of Tat to CycT1 induces cooperative binding of the P-TEFb complex onto nascent HIV-1 TAR RNA. Here the specific interaction between Tat prote...

Short basic peptides from the HIV Tat protein bind specifically to a bulge region in TAR RNA, with a single arginine residue providing the only sequence-specific contact. The free amino acid arginine also binds specifically to TAR. Previous circular dichroism (CD) experiments suggested that peptide binding induces a conformational change in TAR. Here we confirm this observation using single arg...

A series of neomycin dimers have been synthesized using "click chemistry" with varying functionality and length in the linker region to target the human immunodeficiency virus type 1 (HIV-1) TAR RNA region of the HIV virus. The TAR (Trans-Activation Responsive) RNA region, a 59 bp stem-loop structure located at the 5'-end of all nascent viral transcripts, interacts with its target, a key regula...

Twenty-five years ago, cigarette smokers in the United Kingdom smoked plain cigarettes with an average tar yield of probably about 35 mg. Now smokers predominantly smoke filter cigarettes and average tar yields have been reduced by half. Epidemiological evidence comparing mortality in smokers of differing types of cigarettes is reviewed. Compared with smokers of higher tar plain cigarettes, smo...

In the present work, the air-steam biomass gasification model with tar has been developed based on the equilibrium constants. The simulation results based on two different models (with and without tar) have been validated by the experimental data. The model with tar can well predict the tar content in gasification; meanwhile, the predicted gas yield (GY), based on the model with tar, is much cl...

Figure 31 TEM micrographs of water borne polymer nanocomposite (WB PNC) emulsions.49 Figure 34 The reaction of an isocyanate with a compound containing hydroxyl functionality results in the formation of a polyurethane.. Introduction Coal tar is derived from crude coke oven tar that is a by-product of the combustion of coal in steel manufacturing. The crude coke oven tar is then refined, through...

Coal tar is an effective treatment for psoriasis and eczema, but it contains several carcinogenic compounds. Occupational and animal studies have shown an increased risk of cancer after exposure to coal tar. Many dermatologists have abandoned this treatment for safety reasons, although the risk of cancer after coal tar in dermatological practice is unclear. This large cohort study included 13,2...

The trans-activating responsive (TAR) RNA element located in the 5' untranslated region of the HIV-1 genome is a 57-nt imperfect stem-loop essential for the viral replication. TAR regulates transcription by interacting with both viral and cellular proteins. RNA hairpin aptamers specific for TAR were previously identified by in vitro selection [Ducongé,F. and Toulmé,J.J. (1999) In vitro selectio...

Transcriptional activation by the HIV-1 Tat protein requires specific residues in the hexanucleotide loop and trinucleotide bulge of the TAR RNA stem-loop structure found in the 5'-untranslated leader of all viral transcripts. Tat directly contacts residue U 22 in the bulge and is thought to act in concert with cellular factors bound to the loop. We find that HeLa nuclear extracts contain two s...