Essay !2 - Potential advantages of multidomain construction (Proteomics)- Code : KSI0002
< Poteintial advantages of multidomain construction with regard to the proteomics >
Sangin Kim
Problem> Why proteins have the multidomain and what is the meaning?
1. Multidomain construction makes it simple to evolve a new function
- Simple mutations of existing proteins has limitation to acquire new functions - TIme and range
- New functions can be created at a stroke by taking 2 existing functions & combining them
> Complementary functions & combining them -> Complementary functions and interfacial rearrangement
- Bifunctional enzyme can be created by taking the genes for 2 enzymes and fusing the together
2. Multidomain construction make it simple to introduce control and regulation
- Allosteric regulation
- Covalent modification - Signal transduction & Protein - protein interactions
3. Multidomain construction makes an effective enzyme
- Enzyme catalyzed reactions need multiple steps ( Conformational changes )
- A simple rearrangement of a new residues ni a hinge rather than a restructing of the domain is favorable
4. Multidomain construction simplifies folding & Assembly & stablizes the protein
- Most modular proteins fold each module independently.
- Folding complexity is very approximately proportional to n^3 where n is the number of amino acid numbers
- A large protein would be expected to fold up much more slowly than a small protein
- 2 Domains of size n should fold up roughly 8 times faster than a single domain size 2n.
Reference
1. Protein sciences book - Introduction to protein 6th edition .