Exam 3 Drugs & Conditions

Leucine zipper

Dimeric transcriptional regulators that insert alpha-helices into the major groove

Netropsin

Antibiotic that binds to A-T rich regions (AATT) in the minor groove

Triplex-forming oligonucleotide (TFO)

Third strand of DNA hybridizes to a DNA duplex by binding antiparallel to the target oligopurine strand in the major groove; prevents proteins from binding major groove

Daunomycin

DNA intercalator where -OCH₃ projects into the major groove and the amino sugar projects into the minor groove; chemotherapy drug

Camptothecin

Topoisomerase I inhibitor that works by stabilizing the topoisomerase I-DNA covalent complex, preventing DNA from re-ligating; results in apoptosis

Ciprofloxacin

Quinolone antibiotic that inhibits bacterial topoisomerase II by interfering with the breaking and rejoining of DNA; poisonous

Novobiocin

Coumarin antibiotic that inhibits bacterial topoisomerase II by blocking ATP binding; non-poisonous

Rifampicin

Antibiotic that inhibits bacterial RNA polymerase by binding the beta-subunit and blocking the path of elongating DNA

Bicyclomycin

Antibiotic that inhibits rho-dependent RNA transcription termination in bacteria

Streptomycin

Antibiotic that prevents the transfer of fmet-tRNA to the A site

Tetracycline

Antibiotic that inhibits the binding of aminoacyl-tRNAs to the A site

Clindamycin

Antibiotic that blocks peptide formation at the P site

Azithromycin

Antibiotic that blocks the peptide exit tunnel of bacterial ribosomes

Diphtherial toxin

Disrupts peptide formation in ribosomes by inactivation of elongation factor 2; target of TDaP vaccine

Phosphorylation

Continuous unliganded phosphorylation triggers relentless cell division (cancer) and survival signaling; hyperactive tyrosine kinase; ex. Chronic Myelogenous Leukemia (CML)

Glycosylation

Aberrant glycosylation impairs glucose tolerance and contributes to type II diabetes insulin resistance

Ubiquitination

Addition of polyubiquitin chains flags a target protein for degradation in the proteasome; in Parkinson’s disease, damaged mitochondria cannot be polyubiquitinated, causing an accumulation of damaged mitochondria and eventual apoptosis

Hydroxylation

Lack of HIF-1alpha activation under low oxygen levels results in decreased red blood cell development; lack of iron blocks the activity of HIF-1alpha

Acetylation

Lack of acetylation makes DNA inaccessible (highly condensed chromatin) for transcription, silencing thyroid hormone regulated genes, causing a deficiency in thyroid hormone and goiter