5% of the human genome is genes that add a phosphate to something using ATP (Kinases)
Which of the following residues can be phosphorylated by kinases?
How many different kinases are there (roughly)?
In kinases, DFG & RC motifs are highly conserved
Which domains are commonly found in kinase interacting proteins?
SH3 proteins mediate the assembly of proteins structures by binding to proline rich peptides in them
SH domains modulate protein interactions by recognizing and binding to specific proteins by identifying specific peptide sequences
What is the role of PH domains?
Binding the protein to the ER membrane
Binding the protein to the cell membrane
Binding the protein to nuclear membrane
Membranes form what?
Compartments & permeability barriers
Compartments & osmotic barriers
What mediate membrane functions?
Mitochondiral membranes contail the most proteins, plasma membranes contain the least (Out of Mitochondrial, Plasma and Myelin membranes)
Most integral membrane proteins span the membrane
Integral proteins interact extensively with what?
The hydrocarbon chains of lipids
The phosphate groups of phospholipids
The hydrocarbon tails of phospholipids
Peripheral proteins are bound to the membrane via the head groups of phospholipids
How do we tell how strongly a membrane protein is associated?
Try and disassociate it using detergent
Try and disassociate it using water
Baterial Rhodopsin uses heat to pump protons out of the membrane
How is the hydrophobic core formed in baterorhodopsin?
7 alpha helices
7 beta sheets
3 alpha helices, 4 beta sheets
In the case of the highly conserved 'Membrane Spanning Alpha Helix Structure', what must be on the outside?
The membrane spanning alpha helix structure acts as what?
A scaffold for the active site
The active site
The channel for the active site to move through
Transmembrane helices can be predicted by a long string (or more) of hydrophobic amino acids in their aa sequence
What is used to estimate the free energy change of a residue on transfer of a residue to water (i.e. how much energy does it take to disassociate the aa from the protein)?
A polarity scale
An amino scale
A pH scale
An amino acid with high energy lies buried in a hydrophobic region i.e. the membrane
How large is the hydrocarbon core of the membrane?
What is the name of the 20aa section of an integral protein that spans the membrane?
How is a Hydropathy plot formed?
The free energy change for each 20 aa segement plotted against the first aa in each segment
The free energy change for each 20 aa segement plotted against the last aa in each segment
The free energy change for each 30 aa segement plotted against the first aa in each segment
What is the point of a hydropathy plot?
To find which aa are in hydrophobic areas
To find the window of integral proteins
To find the window of peripheral proteins
The criterion level for a hydropathy plot is +68
What is Porin an example of?
Membrane spanning alpha helices
Membrane spanning beta sheets
Membrane spanning helix/beta sheet structure
What tends to be the features of membrane spanning beta sheet residues?
Alternating hydrophobic and hydrophilic
The polarity of the internal aa in a membrane spanning beta sheet depends on the size
Each sheet in the m.s beta sheet arrangement is hydrogen bonded to its neighbor in a parallel manner