Biochem exam 3 Flashcards
Topoisomerase type 2 inhibitors
doxorubicin (adriamycin)
etoposide (etopopos)
Ellepticine
Topoisomerase type 1 inhibitors
Captothecin
Irinotecan (campto)
Topotecan (hycamtin)
RNA Polymerase 1
transcription of major ribsomal RNA genes
RNA Polymerase 2
transcription of protein-coding genes and some small RNA genes
-Has a carboxy terminal domain with highly conserved repeats
-Binds to TATA binding protein, TFII A, B, E, F, H
RNA Polymerase 3
Transcription of small RNA genes
Primary transcript
unprocessed newly synthesis RNA molecule
Processing of mRNA
splicing out introns and joining exons for continous sequence
-Adding a 5’ cap
-Adding a 3’ cap
-Degration
5’cap
7-methylguanosine link at 5’5 -triphosphate link and protect the RNA from nucleases
-forms binding site for ribosomes
exons
coding regions they can be translated
introns
non coding regions they are transcribe but not translated
group 1 and group 2 introns
self splicing no required additional protein of ATP
-in nucleus, mitochondria and chloroplast
Spliceosomal introns
they are splice by spliceosomes
the most common introns
usually in protein coding regions in eukaryotes genomes
tRNA introns
they are spliced by protein based enzymes
primary trascript is cleaved
by endonuclease
mRNA
messenger RNA encode the AA sequence of all polypeptide found in the cell
exons are joined
by ATP dependent ligase
Alternative splicing
a single gene can yield different peptides depending on the RNA processing
-Particular region can be removed or retained, yielding different mature transcripts
tRNA
transfer RNA they match their anticodon to the mRNA while carrying the specific AA for protein synthesis
rRNA
ribosomal RNA they encode code large and small ribosomal subunits
ribozymes
catalytic RNA molecule act as enzymes
miRNA
microRNA they function is gene regulation
-Short non coding RNA of 22 nucleotides
-bind to specific regions in the mRNA and alter translation
they are synthesized by large precursors
they are proccessed by two riboendonucleases= Drosha and Dicer
ribonucleases
degradation of mRNA
gag
group associated antigen
-encodes for long polypeptide that is then cleave into 6 smaller proteins
pol
polypeptide
they code for protease that cleaves the long polypeptides, reverse transcriptase, integrase to insert the DNA into the host DNA
env
encodes viral enveloped
LTR
long terminal repeats facilitates incorporation of the virus genome to the host DNA
-nucleoside or nucleotide analogous
dine or sine
-zidovudine (AZT)
-didanosine (videx)
reverse transcriptase inhibitors drugs
idinavir, saquinavir
protease inhibitors
-since protease are use to cleave proteins for packing into new viral particles
p-independent
UUU in the 3’ end of transcript RNA polymerase will stop and dissociate the mRNA
p-dependent
CA rich sequence called a rut site
-p protein helicase is proccess until termination is reached
-p-protein helicase will bind to the rut site and separate the mRNA from the DNA template
