What is the function of T antigen?
The large and small tumor antigens (T antigens) are the major regulatory proteins encoded by SV40. Large T antigen is responsible for both viral and cellular transcriptional regulation, virion assembly, viral DNA replication, and alteration of the cell cycle.
Is large T antigen A protein?
The large tumor antigen (also called the large T-antigen and abbreviated LTag or LT) is a protein encoded in the genomes of polyomaviruses, which are small double-stranded DNA viruses. LTag is expressed early in the infectious cycle and is essential for viral proliferation.
Is the TATA box in the promoter?
In molecular biology, the TATA box (also called the Goldberg–Hogness box) is a sequence of DNA found in the core promoter region of genes in archaea and eukaryotes.
How does T7 promoter work?
T7 RNA polymerase is a very active enzyme: it synthesizes RNA at a rate several times that of E. coli RNA polymerase and it terminates transcription less frequently; in fact, its transcription can circumnavigate a plasmid, resulting in RNA several times the plasmid length in size.
What is U3 promoter?
The U3 gene was the first example of a gene transcribed by different polymerases in different organisms. Based on phylogenetic arguments we proposed that a polymerase specificity change of the U3 snRNA gene promoter occurred during plant evolution.
Why is CMV promoter silenced?
The cytomegalovirus (CMV) promoter, a strong promoter often used for transgene expression in mammalian cells in culture, is known to be silenced by DNA methylation and histone deacetylation but there is no report on the role of histone methylations in its regulation.
How many polypeptides are in the T cell receptor complex?
[T cell antigen receptor–structure, expression and function] T cell receptor complex is composed of at least 7 different polypeptides and is one of the most sophisticated receptor.
What is the molecular structure of an antigen?
The molecular structure of an antigen is characterized by its ability to bind to the antigen-binding site of an antibody. Antibodies differentiate between different antigens on the basis of the specific molecular structures present on the surface of the antigen. Most antigens are proteins or polysaccharides.
What is the T-cell receptor complex made up of?
The T-cell receptor complex is made up of antigen-recognition proteins and invariant signaling proteins. The T-cell receptor α:β heterodimer (TCR) recognizes and binds its peptide:MHC ligand, but cannot signal to the cell that antigen (more…)
What are complete antigens or immunogens?
Complete antigens or Immunogens are antigens that elicit a specific immune response. These antigens can induce an immune response by themselves without any carrier particles. These are usually proteins, peptides, or polysaccharides with high molecular weight (greater than 10,000 Da).