MCM_Final_TBL8 Flashcards
(13 cards)
Direct/Enzymatic Repair
Types of Damaged Repaired:
- PYRIMDINE dimers @ O6 position via DNA photolase
- methylguanine via methyltransferase
BER
Types of Damaged Repaired
- single base mismatches
- nondistorting alterations in structure (i.e depurination)
via:
- dna Glycosylases
- endonucleases
- dna Pol B
- DNA ligase
NER
Types of Damaged Repaired : dna DISTORTION
- pyrimidine DIMERS
- BPA-guanine adducts
- cisplatin adducts
via:
- NER protein complex
- dna POL E
- DNA ligase
Condition:
Xeoderma pigmentosm
Mismatch Excision Repair
- mismatch bases in daughter strand
conditions:
- herditary nonpolyposis
- colorectal cancer
Antibiotic: Rifampicin
most potent and broad-spectrum antibiotics
- binding to RNA polymerase (blocks bacterial transcription)
- key component of anti-tuberculosis therapy
-
treats α-amanitin toxin from deathcap mushrooms = liver failure
- via binding to RNA Pol II= disrupts elogonation
Antibiotic: Puromyocin
similar structure to 3’-end of aminoacyl-tRNA, there for it binds to the A site of bacterial ribosomes = terminates bacterial protein synthesis
Antibiotic: Tetracyclines
Inhibits bacterial aminoacyl-tRNA binding to the ribosome small subunit.
Antibiotic: Chloramphenicol &Cycohexamide
Inhibits bacterial peptidyl transferase. (Psite)
Antibiotic: Streptomycin
Causes code to be misread, inhibits initiation at high concentrations.
N-formylmethionyl
- tRNA protein elongation
- transfers from its tRNA in the P site to the amino acid in the A site
aminoacyl-tRNA Synthase
- charges the tRNA = activation
- requires 2 ATP
Wobble Base Pairing
- weaker tRNA-mRNA bonding in the 3rd base
- caused by Inosinate (I)
Cloverleaf Structure
-
AA arm
- esterified via carboxyl group to the 2’-OH or 3’-OH
- Anticodon arm
-
D arm (or D loop contains Dihydrouridine)
- tRNA recognition by aminoacyl-tRNA synthetase
-
TψC arm
- Helps in folding
