Video Experimental Relacionado
Updated: Jun 25, 2026
13:51
The MultiBac Protein Complex Production Platform at the EMBL
Published on: July 11, 2013
Estructura de la poli (A) polimerasa de levadura sola y en complejo con 3'-dATP
J Bard1, A M Zhelkovsky, S Helmling
1Boston Biomedical Research Institute, 64 Grove Street, Watertown, MA 02472, USA.
Science (New York, N.Y.)
|August 26, 2000
Resumen
La estructura cristalina de la poliadenilato polimerasa (PAP) de la levadura revela una disposición única de sus dominios. Esta estructura, unida a un análogo de nucleótido, proporciona información sobre la poliadenilación del ARNm.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Estructural Biología estructural.
- Biología Molecular Biología Molecular
Sus antecedentes:
- La polimerasa poliadenilato [poly(A] (PAP) es esencial para agregar colas de poliadenosina a los ARN mensajeros eucariotas (ARNm).
- Comprender la estructura de la PAP es crucial para elucidar los mecanismos de procesamiento del ARNm.
Objetivo del estudio:
- Para determinar la estructura cristalina de la Saccharomyces cerevisiae poliadenilato polimerasa (Pap1).1. para determinar la estructura cristalina de la Saccharomyces cerevisiae poliadenilato polimerasa (Pap1). para determinar la estructura cristalina de la Saccharomyces cerevisiae poliadenilato polimerasa (Pap1). para determinar la estructura cristalina de la Saccharomyces cerevisiae poliadenilato polimerasa (Pap1). para determinar la estructura cristalina de la Saccharomyces cerevisiae poliadenilato polimerasa (Pap1).
- Investigar la base estructural de la actividad enzimática de Pap1 a través de la formación de complejos con un análogo de nucleótido.
Principales métodos:
- Se empleó cristalografía de rayos X para resolver la estructura cristalina de Pap1.1.
- Se determinaron estructuras tanto para la apoenzima como en complejo con 3'-deoxyadenosine triphosphate (3'-dATP).
Principales resultados:
- La estructura cristalina de Pap1 fue resuelta a una resolución de 2.6 angstroms.
- Pap1 exhibe una estructura de tres dominios que rodea el sitio activo, distinta de las polimerasas dependientes de la plantilla.
- Dos moléculas de 3'-dATP se unen a Pap1, ocupando posiciones para el nucleótido entrante y el extremo 3' del primer de ARNm.
Conclusiones:
- La disposición única del dominio de Pap1 proporciona una base estructural para su adición de nucleótidos no plantillados.
- La unión de 3'-dATP sugiere un mecanismo para la incorporación de nucleótidos y la interacción del primer durante la poliadenilación.
Videos de Conceptos Relacionados
02:41Protein Complex Assembly
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Many viruses self-assemble into a fully functional unit using the infected host cell to...
00:55DNA Helicases
DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates...
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...
01:19Allosteric Proteins-ATCase
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
01:25Nucleic Acid Structure
The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA has a double-helix structure. The...
DNA Structure
DNA has a double-helix structure. The...