| front |
back |
revisions |
lasted changed by |
history |
| poly A tail |
-enhances translation by promoting efficient recycling of ribosomes
-poly= many uses of ribosomes to come! |
0 |
mcs5109 Thu, 23 Oct 2008 00:52:05 GMT |
 |
| Kozak sequences |
-purine bases 3 bases upstream of AUG and G immediately after
-"A/G" NN AUG G |
0 |
mcs5109 Thu, 23 Oct 2008 00:52:05 GMT |
|
| to improve euk translation... |
-Kozak sequences
-poly A tail |
0 |
mcs5109 Thu, 23 Oct 2008 00:52:05 GMT |
|
| scanning |
-ribosome moves in a 5’->3’ direction until it encounters the first 5’-AUG-3’ start codon
-ribosome attaches to 5' end, scans until sees start codon
-does its 'thang' |
0 |
mcs5109 Thu, 23 Oct 2008 00:52:05 GMT |
|
| How do euks recruit ribosomes? |
-5' cap!
-required, actually
-scanning |
0 |
mcs5109 Thu, 23 Oct 2008 00:52:05 GMT |
|
| leaderless mRNA |
-no RBS
:-( |
0 |
mcs5109 Thu, 23 Oct 2008 00:52:05 GMT |
|
| where are RBSs? |
-Usually 3-9 base pairs upstream of 5’ start codon
-complementarity/space affects translational effiency |
0 |
mcs5109 Thu, 23 Oct 2008 00:45:09 GMT |
|
| can an ORF w/o a RBS still get translated? |
-Yes!
-coupled translation
-only if polycistronic
-start codon of downstream ORF overlaps stop codon of upstream ORF
-5’-AUGA-3 contains stop and start sequence |
0 |
mcs5109 Thu, 23 Oct 2008 00:45:09 GMT |
|
| 16S rRNA |
-what mRNA is complementary to in SD sequence
-small ribosomal subunit |
0 |
mcs5109 Thu, 23 Oct 2008 00:45:09 GMT |
|
| Shine-Degarno |
-RBS in prokaryotes
-mRNA complementary to small ribosomal subunit (16S rRNA)
-to position start codon correctly
- |
0 |
mcs5109 Thu, 23 Oct 2008 00:45:08 GMT |
|
| monocistronic mRNA |
-eukaryotic
-1 ORF per mRNA |
0 |
mcs5109 Thu, 23 Oct 2008 00:38:01 GMT |
|
| polycistronic mRNAs |
-prokaryotic
-2 or more ORFs on 1 mRNA
-encode proteins for similar functions |
0 |
mcs5109 Thu, 23 Oct 2008 00:38:01 GMT |
|
| operon |
-A group of distinct genes that are expressed and regulated as a unit
-operator, a promoter, and one or more structural genes that are transcribed together |
0 |
mcs5109 Thu, 23 Oct 2008 00:38:01 GMT |
|
| stop codon |
-nearly universal (pros and euks)
-UAA (ochre), UAG (amber), UGA (opal)
-UAA most common |
0 |
mcs5109 Thu, 23 Oct 2008 00:38:01 GMT |
|
| Met |
-AUG
-start codon in euks |
0 |
mcs5109 Thu, 23 Oct 2008 00:38:01 GMT |
|
| formyl-Met |
-ALWAYS start aa in bacteria |
0 |
mcs5109 Thu, 23 Oct 2008 00:29:52 GMT |
|
| start codons in prokaryotes |
-multiple ones used in bacteria and archae
-AUG most common
-regardless of start codon, always codes for formyl-Met
-AUG
-GUG
-UUG
-AUU
-CUG |
1 |
mcs5109 Thu, 23 Oct 2008 00:30:48 GMT |
|
| ORF |
-continuous, non-overlapping codons |
0 |
mcs5109 Thu, 23 Oct 2008 00:29:52 GMT |
|
| how much energy taken up by protein synthesis? |
-rapidly growing bacteria, 80% of cell's energy for protein synthesis
-50% of cell's weight |
0 |
mcs5109 Thu, 23 Oct 2008 00:29:52 GMT |
|
