RESUMEN
In this study, the ability to tailor the peptide-binding specificity of an RNA was investigated. First, variants of the Rev-response element (RRE) RNA with different specificities toward the natural binding partner, Rev, and two RRE-binding aptamers, the RSG-1.2 and the Kl peptides, were identified. Next, hybrid RRE mutants with combinations of two sets of specificity-altering substitutions were tested for peptide-binding specificity. It was shown that in most cases the results of the combination of individual mutations were of an additive nature, therefore providing a way to manipulate the peptide-binding specificity of an RNA in a predictable manner.
Asunto(s)
ARN Viral/genética , ARN Viral/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Sitios de Unión/genética , Genes env , VIH/genética , VIH/metabolismo , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Conformación de Ácido Nucleico , Unión Proteica , ARN Viral/química , Productos del Gen rev del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen rev del Virus de la Inmunodeficiencia Humana/metabolismoRESUMEN
In this study, the potential to manipulate the peptide-binding specificity of an RNA in a rational manner was investigated. First, variants of the Rev-response element (RRE) RNA with different specificities towards the natural binding partner, Rev, and two RRE-binding aptamers, the RSG-1.2 and K1 peptides, were identified. Next, hybrid RRE mutants with combinations of two sets of specificity-altering substitutions were tested for peptide-binding specificity. It was shown that, in most cases, the results of the combination of individual mutations were of an additive nature, therefore providing a way to manipulate the peptide-binding specificity of an RNA in a predictable manner.
Asunto(s)
Genes env , Péptidos/metabolismo , ARN Viral/química , Productos del Gen rev del Virus de la Inmunodeficiencia Humana/metabolismo , Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/metabolismo , Mutación , Unión Proteica , ARN Viral/metabolismo , Productos del Gen rev del Virus de la Inmunodeficiencia Humana/químicaRESUMEN
Conformational characteristics of 1-butanol incorporated not only in hexagonal and lamellar aggregates formed by a lyotropic liquid crystal composed of sodium octanoate, 1-butanol, and water but also in a thermotropic liquid crystal, 4'-methoxybenzylidene-4-n-butylaniline (MBBA), have been investigated from 2H NMR quadrupolar splittings of the perdeuterated and partially deuterated compounds. In the lyotropic phases, 1-butanol shows strong trans preferences and renders itself extended, and octanoate decreases the trans fraction toward the methyl terminal to fill the inner space of the aggregate on behalf of 1-butanol. In MBBA, 1-butanol prefers globular conformations. This tendency was also indicated from the phase behaviors of 1-butanol/MBBA and 1-decanol/MBBA systems. In the nematic field, two successive C-C bonds of 1-butanol mostly adopt g+/-g+/- conformations, which are formed in the vicinity of the headgroup of 1-decanol in the lamella of the sodium octanoate/1-decanol/water system. A large degree ofconformational freedom near the hydroxyl group of alcohols, being shown by ab initio molecular orbital calculations at the Gaussian-2 level, permits them to change conformation for each environment.