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 .