Transcription Factors and Enhancer-Promoter Interactions

Ribosome and Translation

• The Ribosome conducts the process called "translation."
• The Large Subunit (LS) and Small Subunit (SS) are like the buns of a hamburger with the RNA being the vegeburger between the two, and they only reunite when binding to a mRNA sequence to initiate Translation again.
• The sequence of the cavaties E/P/A is significant.

tRNA and Amino Acids

• The 2nd and 3rd tRNAs have the potential to have any amino acid attached.
• The 1st tRNA will always be bonded to Methionine.
• The peptide is released from the tRNA and the ribosome complex, and mRNA, RFs, LS, and SS all disassociate.

Gene Regulation and Transcription

• E denotes the Enhancer and P denotes the Promoter.
• TFs/GTF interaction allows Enhancer-Promoter Loop formation.
• Gene/Protein making thousands of different enhancer-promoter loops!
• Mistakes in the formation of the BMP4 Enhancer-Promoter Loop can lead to some humans having some webbing between digits.

DNA Structure

• DNA is a Mosaic of different regions.
• 7-methyl Guanine is the simplest 5'-cap and is covalently bonded to three phosphates.

mRNA Processing

• Spliceosome removes introns leaving behind exons and a little bit of the 3' end.
• The 3' end is removed and a polyA tail is added.
• A UTR (Untranslated Region) is present upstream and downstream from the translated region.

Translation

• The ultimate goal of translation is to create a long chain of amino acids—which is by definition a protein (or peptide or polypetide).
• The directionality of peptide synthesis is said to be "N-to-C."
• The 1st aa is Met, the 2nd aa is Phe, etc.
• "Redundant" means that there are fewer amino acids than there are codon combinations, so multiple codons can encode for one amino acid.
• It takes 3 mRNA bases (one codon) to code for each aa.
• To make a peptide of 400 aa would require 400 codons or 1200 mRNA bases.
• Stop Codons do not encode for amino acids, they only signal the ribosome to stop protein synthesis.

tRNA and Amino Acid Attachment

• The 3'-overhang is 4 bases for 19/20 tRNAs.
• The anticodon sequence is written in the 3'-to-5' direction to show how it base pairs with the codon which is written in the 5'-to-3' direction.

Cellular Location

• In eukaryotic cells, Translation takes place in the cytoplasm, not in the nucleus.