x****n
发帖数: 893 | 1 in a study of mutations that reduce the activity of a cytoplasmic enzyme, a
mutation is found that results in substitution of an alanine residue for the
serine residue normally present at position 127 in the enzyme. This
mutation is most likely to reduce the activity of the enzyme by preventing
which of the following?
a. attachment of farnesyl group
b. attachment of n-linked oligosaccharides
c. formation of disulfide bonds
d. phosphorylation of the enzyme
e. targeting of the enzyme to the correct cellular location |
c*******9
发帖数: 122 | 2 A is not right for sure.
I am thinking E: cause golgi adds 0-oligosaccharides to serine and threonine
.
Not sure |
s********o
发帖数: 3319 | 3 D. 100% sure. the key word here is "cytoplasmic enzyme". some protein
kinases require phosphorylation at serine/threonine for activation.
A is for membrane-bound protein.
B &C for extracellular (secretory) protein.
E for example mannose-6 P but not in Serine or Threonine . |
x****n
发帖数: 893 | 4 wow, you are good. thank you!!!
【在 s********o 的大作中提到】
: D. 100% sure. the key word here is "cytoplasmic enzyme". some protein
: kinases require phosphorylation at serine/threonine for activation.
: A is for membrane-bound protein.
: B &C for extracellular (secretory) protein.
: E for example mannose-6 P but not in Serine or Threonine .
|
d*****x
发帖数: 96 | 5 Phosphorylation usually occurs on serine, threonine, and tyrosine residues
in eukaryotic proteins |
