Video Experimental Relacionado
Updated: Jul 25, 2026
06:45
Transmembrane Domain Oligomerization Propensity determined by ToxR Assay
Published on: May 26, 2011
La sensibilidad a la tentoxina de los cloroplastos está determinada por el codón 83 de la subunidad beta de la
A Avni1, J D Anderson, N Holland
1Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel.
Science (New York, N.Y.)
|August 28, 1992
Resumen
La tentoxina, un péptido fitotóxico, inhibe el crecimiento de las plantas al dirigirse al plástido protón-adenosina trifosfatasa (ATPasa). Una mutación específica en el codón 83 del gen atpB confiere resistencia o sensibilidad a la tentoxina en plantas y algas.
Área de la Ciencia:
- Ciencias de las plantas Ciencias de las plantas.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- La tentoxina es un péptido fitotóxico que afecta el crecimiento de plantas y algas.
- Inhibe la subunidad beta de la plastida protón-adenosina trifosfatasa (ATPasa).
Objetivo del estudio:
- Para investigar la base molecular de la sensibilidad y resistencia a la tentoxina.
- Para identificar el sitio genético específico responsable de las respuestas diferenciales a la tentoxina.
Principales métodos:
- Análisis comparativo de genes atpB de especies de Nicotiana sensibles y resistentes a la tentoxina.
- La transformación del cloroplasto en Chlamydomonas reinhardtii para confirmar el papel del codón 83.
Principales resultados:
- Una diferencia de un solo aminoácido (glutamato vs. aspartato) en el codón 83 del gen atpB se correlaciona con la resistencia y sensibilidad a la tentoxina, respectivamente.
- La mutagenesis del gen atpB en el codón 83 en Chlamydomonas reinhardtii hizo con éxito que las algas normalmente resistentes fueran sensibles a la tentoxina.
Conclusiones:
- El codón 83 del gen atpB del plástido es un determinante crítico de la sensibilidad a la tentoxina.
- Este sitio en la subunidad beta de la ATPasa probablemente juega un papel clave en la interacción con la tentoxina sin afectar las funciones catalíticas esenciales.
Videos de Conceptos Relacionados
01:48ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
01:18ATP Synthase: Structure
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
01:24Protein Transport to the Stroma
Chloroplasts are triple membrane structures with an outer membrane, an inner membrane, and a thylakoid membrane, each containing distinct metabolite transporters, membrane translocons, and enzymes. Appropriate sorting and translocating these proteins to their correct membrane systems is essential for chloroplast function.
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
01:11Protein Transport to the Outer Chloroplast Membrane
Chloroplast outer membrane proteins encoded by the nucleus are synthesized in the cytosol. Soon after synthesis, they bind cytosolic factors such as 14-3-3 protein and the Hsp70 chaperones that keep these precursors in an unfolded state until their translocation.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
01:18Protein Transport to the Inner Chloroplast Membrane
Proteins targeted to the inner chloroplast membrane, or plastid proteins, are transported by two general pathways: the stop-transfer and the re-insertion or post-import pathways. Most plastid proteins carry N-terminal transit sequences and internal import sequences targeting it to the specific chloroplast subcompartment. Proteins targeted by the stop-transfer pathway have internal hydrophobic sequences that inhibit their translocation into the stroma. As a result, these precursors are arrested...
01:29Tetanus
Tetanus is a life-threatening neurological disorder characterized by persistent muscle contractions and spastic paralysis. It is caused by Clostridium tetani, a motile, Gram-positive, rod-shaped, obligate anaerobe. These bacteria produce terminal endospores, giving them a distinctive “lollipop” or “tennis-racket” appearance. They thrive in anaerobic environments, such as those found in deep puncture wounds.Once introduced into the body, the spores germinate into vegetative cells. These cells...