Which lipid comprises mycobacterial cell walls?
The cell wall complex contains peptidoglycan, arabinogalactan, mycolic acid, and lipoarabinomannan (LAM). Over 60% of the mycobacterial cell wall is lipid mycolic acid and 50% of the dry weight of the cell wall.
Which drug inhibits transcription in Mycobacterium and is used to treat tuberculosis?
Rifampicin. Rifampicin (RIF) inhibits the transcription of RNA by binding the RNA polymerase B subunit.
How does Mycolic acid enable Mycobacterium tuberculosis in its pathogenesis?
Mycolic acids also allow the bacterium to grow inside macrophages, effectively hiding it from the host immune system. Mycolate biosynthesis is crucial for survival and pathogenesis of M. tuberculosis. The pathway and enzymes have been elucidated and reported in detail.
Which of the following is the causative agent of tuberculosis?
Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis.
What are the 3 major components of the Mycobacterium cell wall structure?
The essential core cell wall structure is composed of three main components: a cross-linked polymer of peptidoglycan, a highly branched arabinogalactan polysaccharide, and long-chain mycolic acids.
Does rifampin affect transcription or translation?
It is found that low doses of rifampicin cause an absolute and differential increase in the rate of synthesis of the specific mRNA for the beta-subunit, suggesting a stimulation of the corresponding gene transcription.
Does rifampicin inhibit translation?
Rifampin (rifampicin) Rifampin inhibits protein synthesis by a very specific inhibition of bacterial DNA-dependent RNA polymerase, thereby blocking the synthesis of mRNA.
Why Mycobacterium is not Gram stain?
Mycobacteria are “Acid Fast” They cannot be stained by the Gram stain because of their high lipid content.
Is Mycobacterium aerobic or anaerobic?
Mycobacterium is a dominant genus in the soil, and all its species are obligate aerobes.
What is the effect of rifampicin on transcription?
Rifampicin binds to the exit channel of the RNA polymerase by making specific contacts that involve the β-subunit of RNA polymerase. Rifampicin blocks the exit channel thereby inhibiting transcription (Campbell et al., 2001).
Is Mycobacterium gram negative or gram-positive?
Mycobacteria are Gram-positive, catalase positive, non-motile, non-spore forming rod-shaped bacteria (0.2–0.6 μm wide and 1.0–10 μm long).
What is the role of cholesterol in the synthesis of steroids?
Cholesterol is an essential component of cell membranes and the precursor for the synthesis of steroid hormones and bile acids. The synthesis of this molecule occurs partially in a membranous world (especially the last steps), where the enzymes, substrates, and products involved tend to be extremely …
Where does the synthesis of cholesterol occur?
The synthesis of this molecule occurs partially in a membranous world (especially the last steps), where the enzymes, substrates, and products involved tend to be extremely … Cholesterol is an essential component of cell membranes and the precursor for the synthesis of steroid hormones and bile acids.
What is the role of cholesterol in cell membrane synthesis and differentiation?
Cholesterol plays an essential role in cell membrane synthesis and in cell growth and differentiation. In mammalian cells, cholesterol can be synthesized from acetate precursors or taken up from dietary or exogenous sources. The major catabolic route for disposal of cholesterol involves conversion i …
What enzymes are involved in cholesterol biosynthesis?
In this regard, the structure and catalytic mechanism of the enzymes involved in cholesterol biosynthesis, from the initial two-carbon acetyl-CoA building block, will be reviewed and their current pharmacological importance discussed.