Lecture 14- Protein regulation by small PTMs Flashcards
what does phosphorylation do to molecules
causes a -2 shift in charge, which can lead to conformational change or altered interactions
targets for phosphorylation
often -OH side chain groups, e.g. Ser and Thr
can be basic or acidic residues, but harder to detect and less common
how many human kinases are there
518
example of a protein kinase and what it phosphorylates
PKA- PhK, which then phosphorylates PG, breakdown of glycogen into G1P
mechanism of PKA action
‘encloses’ ATP, ‘hinge’ like function when N lobe moves to accommodate ATP, locks it into position and the first 2 phosphates are stabilised
gamma phosphate interacts with the C subunit via Mg2+
substrate recognition at the binding group
what removes phosphates
phosphatases
how many human phosphotases are there
189- more tendency to be generalised, but aren’t always
example of an important use of kinases
in plant immunity- can recognise bacteria via flagellins, kinase pathway, triggering of CDK
oxidative burst and eventual transcriptional reprogramming by TF activation
example of bacterial defence against immunity from kinases
AvrPro, kinase inhibitor
what is methylation
addition of a -CH3 group
what does methylation do
increases hydrophobicity
where does methylation usually act
N and C termini of acidic and basic residues
what enzymes add and remove methyl groups
methyl transferases- add
demethylases- remove
cofactor in methylation
SAM/SAH
