alpha thalessemia: results in severe anemia and death
note-alpha globin is oxygen carrying component of Hb
What are the components of a Hb molecule?
two beta globins and two alpha globins, 4 heme groups
Where is the beta globin gene located?
What happens if beta globin is mutated?
sickle cell anemia
Where is epsilon globin exp?
Where is A-gamma and G-gamma globins exp?
What are the adult Hb?
alpha, beta, delta globin
modified RNA base in T loop of tRNA; linkage btw uracil and ribose is changed from C-N bond to C-C bond
T loop of tRNA; modified RNA base
modified RNA base; deaminated adenine base whose nucleoside is inosine
What are the most common modified RNA bases?
pseudouridine and nucleosides w/ 2'-O-methylribose
What is unique about the 5' cap of mRNA?
linked to mRNA via 5'-5' triphosphate linkage to first transcribed nucleotide
What is located in the 3'UTR of mRNA?
polyA signal (site of cleavage), binding sites for prot, binding sites for miRNA, siRNA, and reg RNA
RNAse H and FENs
enz w/ endonucleolytic activity that remove the primer in lagging strand synth
DNA clamp prot; processivity factor for DNA pol delta by encircling DNA as a trimer which creates a topological link to the genome
single origin of replication in prok; 245 bp long w/ conserved seq (four 9-bp repeats and three 13-AT rich bp repeats)
initiation factor in prok DNA synth; binding cooperative (once one DnaA binds to a OriC repeat, tons of others bind)
How does DnaA prot mediate sep of DNA strands in prok?
acts on three AT rich regions of OriC
binds to open OriC in prok; delivered by DnaC; completes pre-priming complex; has helicase activity
primase for prok DNA synth
termination seq in DNA repl in prok; when bound to Tus prot, terminates DNA synth
polarity of action
Ter sites; will arrest a rep fork approaching the Ter site from one direction but will allow unimpeded fork mvmt through the Ter site from other direction
RNase H activity
ribonuc that degrades the RNA from RNA-DNA hybrids in rt of RNA template; func as endonuc and exonuc
group-specific antigen; codes for core and structural prot of retrovirus (i.e. viral capsid)
codes for rt, protease, and integrase; synth viral DNA and integration into host DNA after infection
codes for retroviral coat prot; plays role of entry of virion into host cell
dimer RNA; cap at 5' and polyA at 3'; has terminal noncoding regions and internal coding regions
R region (retroviral)
forms a direct repeat at both ends of genome
non-coding region, first part of genome to be rt; forms 3' end of provirus genome
18nt complementary to 3' of specific tRNA primer used by virus to begin rt
long, non-transL region downstream of transC start site and present at 5' of all virus mRNAs
short A/G run; initiates strand synth in rt
non-coding region; forms 5' end of provirus after rt; contains promoter elements used in transC of provirus
How do oncoviruses originate?
"retroviruses that contain oncogenes"; viral DNA incorporates a section of host DNA (contains genes for growth promotion called proto-oncogenes) into its own DNA; increased transC caused by LTRs of virus cause increased growth of infected cell
bind to basic promoter seq facilitating RNA binding
bind to seq distant from basic promoter and have specific roles
What are the roles of specific TF?
1. modulate efficiency of initiation
2. mediate signal response
3. regulate gene exp
4. bind other reg prot
Key pts in euk tRNA synth
1. internal promoter-binding sites for TF and RNA pol 3
2. transcription products contain promoter (start pt upstream of promoter)
Upstream promoter elements
CAAT and G/C box; fixed position/orientation but located distally upstream from TATA (core promoter element)
sigma factor (euk transC)
TF that binds to TATA core promoter element; binding of RNA pol follows
elements in transC that are not covalently linked to DNA