LO:
•become familiar with the concept of modular proteins
•Learn about their biological signifcance
•Learn about the signifcance of protein modularity in protein interactons and regulaton
Protein structure II:
•Most proteins have a domain structure
3D scaffolds repeated = domain
Domains are identified using amino acid sequence profiles
- Sequences in between variables some of the AA are conserved in seq same overall
structures/ fold
- Powerful way in discovering certain protein structures/ domains
Domain: a folded structural unit; the sequence need not be contguous e.g. MHC II
Module: a domain with a contguous sequence, repeatedly used in diverse proteins e.g. F3
Repeat: a unit that does not fold in isolaton; several copies are needed e.g. Leu-rich repeat
Folding is important, critcal for a domain module = no gaps
Repeats = no folding on its own
Protein domain I
Fewer domains give rise to many diferent types of protein – prokaryotes
•Prokaryotes ~2/3 proteins contain more than one domain
–E.coli proteome made up from combinatons of about 400 domains
•Eukaryotes ~3/4 proteins are multdomain proteins
–Eukaryote genome has about 600-700 domains
•Many (but not all) domains are shared between Bacteria, Archaea, and Eukaryotes
Protein Domain II
•Sometimes separate genes in prokaryotes fuse to become a single mutli-domain protein in
eukaryotes
–e.g. five E.coli genes in synthesis of aromatic amino acids fuse to one in Aspergillus
nidulans
•Domain combinations are not random
–Few domains combine with many
–Most combine only with one or few other domains
•become familiar with the concept of modular proteins
•Learn about their biological signifcance
•Learn about the signifcance of protein modularity in protein interactons and regulaton
Protein structure II:
•Most proteins have a domain structure
3D scaffolds repeated = domain
Domains are identified using amino acid sequence profiles
- Sequences in between variables some of the AA are conserved in seq same overall
structures/ fold
- Powerful way in discovering certain protein structures/ domains
Domain: a folded structural unit; the sequence need not be contguous e.g. MHC II
Module: a domain with a contguous sequence, repeatedly used in diverse proteins e.g. F3
Repeat: a unit that does not fold in isolaton; several copies are needed e.g. Leu-rich repeat
Folding is important, critcal for a domain module = no gaps
Repeats = no folding on its own
Protein domain I
Fewer domains give rise to many diferent types of protein – prokaryotes
•Prokaryotes ~2/3 proteins contain more than one domain
–E.coli proteome made up from combinatons of about 400 domains
•Eukaryotes ~3/4 proteins are multdomain proteins
–Eukaryote genome has about 600-700 domains
•Many (but not all) domains are shared between Bacteria, Archaea, and Eukaryotes
Protein Domain II
•Sometimes separate genes in prokaryotes fuse to become a single mutli-domain protein in
eukaryotes
–e.g. five E.coli genes in synthesis of aromatic amino acids fuse to one in Aspergillus
nidulans
•Domain combinations are not random
–Few domains combine with many
–Most combine only with one or few other domains
