How does chloramphenicol acetyltransferase work?

How does chloramphenicol acetyltransferase work?

Chloramphenicol acetyltransferases (CATs) are enzymes that covalently modify CAM, rendering it inactive against its target, the ribosome, and thereby causing resistance to CAM.

Where is chloramphenicol acetyltransferase found?

Chloramphenicol binds in a deep pocket located at the boundary between adjacent subunits of the trimer, such that the majority of residues forming the binding pocket belong to one subunit while the catalytically essential histidine belongs to the adjacent subunit.

Does chloramphenicol target bacterial protein synthesis?

Chloramphenicol inhibits microbial protein synthesis by binding to the 50 S subunit of the 70 S ribosome and inhibiting the action of peptidyl transferase, thus preventing peptide bond formation.

How does chloramphenicol acetyltransferase inactivate chloramphenicol?

CATs inactivate chloramphenicol via acetylation, which is the most prevalent mechanism of resistance to chloramphenicol in bacteria (Shaw, 1983; Murray and Shaw, 1997; Schwarz et al., 2004). CATs have been described in both gram-positive and gram-negative bacteria.

What is the cellular target of chloramphenicol?

Chloramphenicol stops bacterial growth by binding to the bacterial ribosome (blocking peptidyl transferase) and inhibiting protein synthesis. Chloramphenicol is lipid-soluble, allowing it to diffuse through the bacterial cell membrane.

What is CAT gene?

The CAT gene provides instructions for making pieces (subunits) of an enzyme called catalase. Four identical subunits, each attached (bound) to an iron-containing molecule called a heme group, form the functional enzyme.

What is chloramphenicol acetyltransferase gene?

Chloramphenicol acetyltransferase (CAT) is the classic example among reporter genes. The enzyme catalyzes the transfer of an acetyl remnant of acetyl CoA to chloramphenicol. The cell lysate to be examined is incubated with acetyl CoA and [14C]-labeled chloramphenicol.

What enzyme is encoded by chloramphenicol resistance?

chloramphenicol acetyltransferase (CAT)
The primary mechanism of resistance to chloramphenicol is due to the presence of chloramphenicol acetyltransferase (CAT), an enzyme which catalyzes the acetylCoA-dependent acetylation of the antibiotic at the C-3 hydroxyl group (58).

Which ribosomal site does chloramphenicol work in?

peptidyl transferase center
Antibiotic chloramphenicol (CLM) binds with a moderate affinity at the peptidyl transferase center of the bacterial ribosome and inhibits peptide bond formation.

What are the names of the three sites where tRNA molecules bind to the ribosome?

Ribosome Structure The three tRNA sites are labeled P, A, and E. The P site, called the peptidyl site, binds to the tRNA holding the growing polypeptide chain of amino acids. The A site (acceptor site), binds to the aminoacyl tRNA, which holds the new amino acid to be added to the polypeptide chain.