What is chloramphenicol acetyltransferase gene?
Chloramphenicol acetyltransferase (or CAT) is a bacterial enzyme (EC 2.3. 1.28) that detoxifies the antibiotic chloramphenicol and is responsible for chloramphenicol resistance in bacteria.
How Chloramphenicol acetyltransferase works?
This is a bacterial gene that evolved to neutralize the antibiotic chloramphenicol. To neutralize it, CAT transfers acetyle groups to chloramphenicol and thus changes its shape into a harmless form. Molecular biologists were quick to recognize this enzyme could be used as a reporter protein in eukaryotic cells.
What enzyme is encoded by chloramphenicol resistance gene?
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).
Is CAT a reporter 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.
Is chloramphenicol Gram positive or negative?
Chloramphenicol is a broad-spectrum antibiotic whose spectrum includes several gram-positive and gram-negative bacteria, spirochetes, and Rickettsiae.
How do bacteria become resistant to chloramphenicol?
The most common mechanism of resistance to chloramphenicol in bacteria is its enzymatic inactivation by acetylation mainly via acetyltransferases or, in some cases, by chloramphenicol phosphotransferases (1, 56).
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 kanamycin resistance gene?
In bacteria, resistance to kanamycin is attributed to three mechanisms. One mechanism involves an aminoglycoside-modifying enzyme carried by transposons (22). The second mechanism is specific methylation of rRNA. Modification of the rRNA at position 1405 or 1408 was responsible for kanamycin resistance (5).
Is chloramphenicol gram-positive or negative?
Is chloramphenicol broad or narrow spectrum?
Chloramphenicol is a synthetically manufactured broad-spectrum antibiotic.
What is the zone of inhibition for chloramphenicol?
Mode of action: Inhibits protein synthesis in gram variable bacteria. Intermediate zone of inhibition in mm: 13–17.
How does chloramphenicol resistance gene work?
What is the antibiotic resistance gene?
Antibiotic resistance genes are often located on plasmids or transposons and can be transferred from cell to cell by conjugation, transformation, or transduction. This gene exchange allows the resistance to rapidly spread throughout a population of bacteria and among different species of bacteria.
Does chloramphenicol target gram-positive or negative?
Chloramphenicol is used as therapy in systemic and local infections. Many Gram-positive and Gram-negative bacterial genera are susceptible to chloramphenicol, but most strains of Pseudomonas aeruginosa are not.
How long is the LacZ gene?
3075 base pairs
LacZ gene size
| Value | 3075 base pairs |
|---|---|
| Organism | Bacteria Escherichia coli |
| Reference | Benno Muller-hill, 1996, The Lac Operon: A Short History Of A Genetic Paradigm, Publisher: Walter de Gruyter. Berlin. New York. Part 3.2 pp.134 |
| Entered by | Uri M |
| ID | 102070 |
Is LacZ a fluorescent?
Fluorescent proteins, luciferases, and LacZ are all recombinant protein-based reporters that can be used for localization or imaging studies.
What is chloramphenicol acetyltransferase?
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 [ 14 C]-labeled chloramphenicol.
What is chloramphenicol acetyltransferase (CAT) resistance?
The chloramphenicol acetyltransferase (CAT) gene is usually encoded on a plasmid or transposon and may transpose to the chromosome. Surprisingly, in view of the very limited use of chloramphenicol, resistance is not uncommon, even in Esch. coli, although it is most frequently seen in organisms that are multiresistant. Thomas E. Renau,
What is the mechanism of resistance to chloramphenicol?
Chloramphenicol acetyltransferase The major mechanism of resistance to chloramphenicol is the production of a chloramphenicol acetyltransferase which converts the drug to either the monoacetate or the diacetate. These derivatives are unable to bind to the bacterial 50S ribosomal subunit and thus cannot inhibit peptidyl transferase activity.
How is acetylation activity measured in chloramphenicol (cat)?
The CAT assay involves monitoring acetylation of radioactively labeled chloramphenicol on a TLC plate; CAT activity is determined by looking for the acetylated forms of chloramphenicol, which have a significantly increased migration rate as compared to the unacetylated form. ^ Engel J, Prockop DJ (1991).