Protein Transport + Secretion Flashcards
How many proteins does the cell membrane have?
300
How many proteins does the outer membrane have?
50
How many proteins does the periplasm have?
100
T4S
Conjugate pilus
Fla/T3S
Effector/toxins
CU
Pilus
T2S
Hydrolytic enzymes, toxins, type IV pilus
Components of Sec system
-Leader peptide on preprotein (SIGNAL)
- Signal recognition particle (SRP)
Preprotein
Not in shape yet
Cleavage site
leader peptide cleaved once transported across membrane
N-terminal
start of protein/peptide
–> recognizes leader
–> trafficks to SecYEG to interact and be transported across membrane
Chaperone
SecB
Membrane complex
SecYEG
ATPase
SecA
SecB 2 modes of binding
Premiscuous binding to polypeptide
- specific binding partner (SecA)