probio Proper protein folding and Folds/motifs

How does coding for antibodies work

Variable and constant portions are coded by seperate gene regions, then assembled on site in response to antigens. high mutation and mulitple assembly units allows for different variable proteins

DNA-binding proteins:

complexes that catalyize replication/transcription

homeodomain

largely-conserved protein that controls where body parts go during development - interacts with major groove for more chem info

coiled-coil motif (leucine zipper)

hydrophobic residues - binds to dna and proteins for dimerization

HLH proteins

helix-loop helix proteins

fibrous proteins

long fiber proteins, such as collagen, cytoskeleton fibrils

holdase

prevent collapse and aggregation of unfolded proteins, provide conditions for folding

foldase

catalyze folding/unfolding

Hsp70

heat shock protein 70 - working on polypeptide immediately when synthesis

DnaK

hsp70 in bacteria

hsp 40

assists hsp 70

co translational folding proteins

CCT, TCP-1, TriC in euks, GroEL and Gro-ES in proks: environment for folding

Modules in proteins to be folded

correspond to specific functional domains

ssa

viability and temperature protection

ssa2

nearly identical, constitutive

ssa1,3,4

divergent, heat shock inducible

ssb

non essential protein folding, both ssb1 and 2 are nearly identical and heat shock non-inducible

ssc

mitochondrial protection

kar2 and BiP

protection in ER

Ydj1

Hsp40 working with ssa

Zuo1

ssb hsp40: helped by Ssz1 (Hsp70)

Sis1

hsp40 working with ssa

RAC

ribosome associated chaperone complex - in yeast

ribosome, zuo1, ssb, ssz1, and NAC

NAC

nascent polypeptide associated complex: in RAC

Do mammalian cells contain orthologs of RAC system?

Nac and rac yes: zuo1 and ssz1, but not ssb

GroEL and GroES in bacteria

14 7×2 GroEl rings, GroES Lid

Describe the genes encoding euk and prok chaperonins

TCP-1, TriC and Cct have 8 subunits that are coded by different genes (CCT1-8): forms a double barrel ring with a cavity.

GroEL all by same

Euk/prok chaperonin binding behaviors?

Cct only binds a fraction of proteins while GroEL binds a all with nonpolar surface residues