This document discusses protein domains and their evolutionary relationship between diverse proteins. Protein domains are conserved parts of a protein sequence that determine structure and function. Domains act as compact, independently folding modules that provide specific catalytic and binding sites and serve as building blocks for large protein assemblies. Domains are found across different proteins and have been adapted through evolution, with some folds favored over others as they represent stable arrangements. Bioinformatics approaches like the Protein Data Bank and CATH classify protein structures into families and domains to better understand evolutionary relationships and comparisons between proteins.

1. Evolutionary Relationship between
Diverse Protein with similar Domain
By: Rishabh Paliwal
B100980BT

2. What is Domain?
 stable units of Protein.
 conserved part of a given protein sequence.
 decides structure and function of Protein.
 folded 3-D compact structure with stability.
 length vary between 25 to 500 amino acid.

3. Example
 Zinc finger with metal ion or disulfide bridges.
 functional domain like calcium-binding EF
hand domain in calmodulin.

4. Domains in Protein
 Compact structural domain are found in diverse
Protein.
 Independent folding.
 Naturally multifunctional and multidomains.
 Provides specific catalytic and binding sites.
 Serves modules for building up large assemblies.

5. Example
 pyruvate kinase to regulate F-6-P to pyruvate.
 contains
1. All β regulatory domain
2. An α/β substrate binding domain
3. An α/β nucleotide domain
 same as enzyme.

6. Evolution modules
 new sequences are adapted from pre-existing
sequence.
 domains as modules.
 C and N terminal become close during evolution
Found in all form of life.
 repetition of domain in diverse protein

7. Continue….
 found among cell surface, cytokinin receptor,
extracellular protein and matrix.
 molecular evolution in similar sequence and
structure.
 some folds may be favored than others as they
represent stable arrangements of secondary
structures and some proteins may converge
towards these folds over the course of evolution.

8. Bioinformatics Approach
 Protein Data Bank
 Deposited more than 90,000 experimentally
determined protein structure.
 Various Set of similar structure.
 Classified in families to understand
evolutionary relationship and comparison.
 Algorithm for assigned domain with 3-D
structure

9. Continue….
 CATH
 Has 800 fold families
 Super-fold families with at least three
populated without significant sequence
similarity.
 Most populated is α/β barrel super-fold