Sliding clamp

Con il termine DNA clamp o sliding clamp , vengono identificate una serie di proteine che assolvono la funzione di fattori di promozione o di fattori di processamento nella replicazione del DNA. Queste proteine mantengono le DNA polimerasi agganciate al filamento di DNA da replicare, con un modello di funzionamento . A DNA clamp, also known as a sliding clamp , is a protein fold that serves as a processivity-promoting factor in DNA replication. As a critical component of the DNA polymerase III holoenzyme, the clamp protein binds DNA polymerase and prevents this enzyme from dissociating from the template DNA strand.

Sliding clamps allow DNA polymerases to remain attached to their DNA template. Parole chiave: duplicazione, DNA polimerasi, applicatori di pinza (clamp loader), processività, continuità di processo.

Introduzione Nel nostro genoma, sono. Biochemical Society Transactions . Moltissimi esempi di frasi con sliding clamp – Dizionario italiano-inglese e motore di ricerca per milioni di traduzioni in italiano. Cells use an amazing trick when they copy their DNA: they tether their molecular machines to a ring-shaped clamp, which slides along the DNA and keeps the machinery focused on its task. This leads to remarkable increases in efficiency. For instance, by tethering their DNA polymerase to a sliding clamp , bacteria increase . Chromosomal replicases are multiprotein assemblies composed of a DNA polymerase and several accessory proteins and are characterized by remarkable speed and processivity.

Although these proteins have different oligomeric states, they all possess a general pseudo-sixfold ring-shaped structure.

To achieve the high degree of processivity required for DNA replication, DNA polymerases associate with ring-shaped sliding clamps that encircle the template DNA and slide freely along it. The closed circular structure of sliding clamps necessitates an enzyme-catalyzed mechanism, which not only opens them for assembly . Looking for online definition of sliding clamp in the Medical Dictionary? Meaning of sliding clamp medical term. What does sliding clamp mean?

Confers DNA tethering and processivity to DNA polymerases and other proteins. Acts as a clamp , forming a ring around DNA (a reaction catalyzed by the clamp - loading complex) which diffuses in an ATP-independent manner freely and bidirectionally along dsDNA. Initially characterized for its ability to contact the catalytic . DNA bound in the ring is bent 22 . We present structures for the ATP-bound state of the clamp loader complex from bacteriophage T bound to an open clamp and primer- template . Crystal structure of a DNA polymerase sliding clamp from a Gram-positive bacterium. The first sliding clamp structure determined was E. It functions by adding nucleotide triphosphate (dNTP) residues to the 5'-end of a growing DNA chain, using a complementary DNA as template.

Bacterial DNA clamps observed to date form . The elongation factor beta- clamp , also called . In addition to the catalytic components, the DNA sliding clamp , PCNA ( proliferating-cell nuclear antigen), plays a pivotal role in binding and co- ordinating these enzymes at sites of lagging-strand replication. Structural studies in eukaryotic and archaeal systems have revealed that PCNA-binding proteins can adopt different .

The peptide-binding pocket of sliding clamps is located between two domains on each protomer ( 10). The binding pocket of the bacterial β-clamp is located between domains II and III, as demonstrated by structures of β bound to the δ- clamp loading subunit (11) and the β-Pol IV complex (1 12).