Video Experimental Relacionado
Updated: May 7, 2026
11:40
Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy
Published on: June 25, 2013
La sinapsis de los sitios de adhesión durante la recombinación lambda integrativa implica la captura de un ADN
E Richet1, P Abcarian, H A Nash
1Laboratory of Molecular Biology National Institute of Mental Health Bethesda, Maryland 20892.
Cell
|January 15, 1988
Resumen
Los sitios de adhesión bacteriana (attB) adquieren la Int recombinasa a través de la colisión con los intasomas virales, no la unión directa. Esta captura de ADN durante la integración lambda es impulsada por proteínas, no dependiente de la homología.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Genética La genética.
- Virología Virología.
Sus antecedentes:
- La integración lambda de los bacteriófagos requiere de la recombinasa Int para unirse y dividir los sitios de unión del ADN viral (attP) y del huésped (attB).
- El mecanismo preciso por el cual el ADN attB adquiere la Int recombinasa para la integración no ha sido claro.
Objetivo del estudio:
- Aclarar el mecanismo de adquisición de la recombinasa Int por el sitio attB durante la integración lambda.
- Investigar el papel de la homología del ADN y las interacciones proteína-ADN en las sinapsis attB-attP.
Principales métodos:
- Pruebas de huella de ADN para evaluar la unión Int-DNA.
- Un nuevo ensayo de escisión del ADN para monitorear la dinámica de recombinación.
- Análisis de las interacciones attB-attP en presencia de ADN competidor.
Principales resultados:
- El sitio bacteriano attB no se une de manera estable a la recombinasa Int en presencia de ADN competidor.
- attB obtiene la recombinasa Int a través de la colisión con el intasoma, un complejo formado en el sitio de attP.
- La captura de attB por el intasoma attP es independiente de la homología del ADN, impulsada por las interacciones de las proteínas.
Conclusiones:
- La integración lambda implica un nuevo mecanismo en el que el attB es capturado por el attP intasoma a través de interacciones mediadas por proteínas.
- La sinapsis entre attB y attP se rige por las interacciones proteína-ADN y proteína-proteína, no por la homología de la secuencia de ADN.
- Este hallazgo aclara la dinámica de la recombinación específica del sitio y la formación del ensamblaje de nucleoproteínas.
Videos de Conceptos Relacionados
03:01The Replisome
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
02:31Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
02:53Conservative Site-specific Recombination and Phase Variation
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
01:03Single-Strand DNA Binding Proteins
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
03:01The Replisome
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
01:15Activation of Integrins
Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.