An enveloped, negative-sense, single-stranded RNA virus. The genome is segmented into eight distinct structural and non-structural coding regions, allowing for rapid reassortment (antigenic shift).
Viral entry is mediated by the Hemagglutinin (HA) surface glycoprotein, which binds specifically to sialic acid residues on the host respiratory epithelium.
Drugs like Oseltamivir competitively inhibit the active site of the viral Neuraminidase (NA) enzyme, strongly stabilizing the complex through electrostatic interactions with highly conserved arginine residues (Arg118, Arg292, Arg371). This prevents the cleavage of terminal sialic acid, trapping virions at the cell membrane.
An obligate pathogenic bacterium characterized by an exceptionally thick, waxy cell envelope rich in mycolic acids, conferring profound resistance to standard Gram stains and broad-spectrum antibiotics.
Isoniazid is a prodrug requiring activation by the mycobacterial catalase-peroxidase enzyme, KatG. The resulting INH-NAD adduct is a tight-binding competitive inhibitor of InhA, a critical enzyme in the FAS-II pathway essential for mycolic acid biosynthesis.
A positive-sense, single-stranded RNA virus. Replication is driven by the RNA-dependent RNA polymerase (RdRp), primarily composed of nsp12.
Remdesivir (GS-5734) is an adenosine analogue prodrug. Incorporated into nascent viral RNA by the RdRp, a 1'-cyano group causes a steric clash, stalling the polymerase exactly three nucleotides downstream. This delayed chain termination successfully evades the virus's built-in exonuclease proofreading activity (nsp14).