Lectures

Question 1

Lecture 1 - cryoEM

Answer 1

negative stain(heavy metal contrast image)
3dbuild- class images(orientations), build u
issues- similar views, small classes(disregarded), overseen orientations
deterime build- angular reconstruction, projection matching, fourier transform

Question 2

Lecture 2- GroEL

Answer 2

Structure- Apical, Intermediate, equalatorial domain, hinges between.
ATP binding- comparisiion of cryoem low res structure with crystal structures. weakens the ring-ring interface. therefore ATP binding allows rings to behave asymmetrically
ATP hydrolysis- rotation of ED, distrupts B strands between trans EDs, radial expansion of rings

Single-particle cryo-EM identifies seven ATP-bound structures of
GroEL chaperonin
• Analysis of structures suggests trajectory of domain movements
triggered by ATP binding
• The structures delineate a mechanism for mechanical unfolding of
polypeptide substrate
• Model suggests an intermediate conformation binding substrate and
GroES simultaneously