- Levels of structure:
- Primary structure - the sequence of amino acids
- Secondary structure - the local interactions and structure
- Tertiary structure - the global interactions and structure (indication of the function of the protein)
- Quaternary structure - structure resulting from multiple protein molecules interacting
- Protein folding problem - given the primary structure of the protein we
would like to predict how the protein folds resulting in the tertiary structure.
- This problem is not solved yet. There have been many different approaches
on many different levels from: physics to chemistry to biology.
- Some rules of thumb have been created/discovered to aid the prediction of the tertiary structure. For instance: amino acids can be hydrophobic (repelled by water) or hydrophilic (atracted to water).
- This problem is not solved yet. There have been many different approaches
on many different levels from: physics to chemistry to biology.
Some of the problems are:
- We do not know which codons are introns and which are
exons. The introns
are not part of the protein building process, exons are.
- When reversing the DNA transcription to mRNA process we get cDNA. cDNA
consists of only exons. This makes finding the genomic DNA that gave rise to a
specific protein difficult since we do not know what introns were in the
original DNA.
- Promoters are not well understood. This makes finding the begining of a gene difficult.