Protein Structure and Function

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What is the primary advantage of using cryo-electron tomography (Cryo-ET) in understanding protein structures?

To purify proteins and remove interacting partners

To understand the intricate structures of proteins through isolation

To directly determine macromolecules within their native cellular environment (correct)

To identify new components through fixation artifacts

What can be improved during protein isolation to obtain better results?

Using faster freezing techniques

Using different grids to change surface properties

Using detergents to change the surface properties

All of the above (correct)

What is a characteristic of proteins in cells?

They are present in relatively large quantities

They are only interactive with cytoskeletal structures

They are present in relatively small quantities (correct)

They are static and unchanging

What is the primary goal of cryo-electron tomography?

To determine macromolecules within their native cellular environment Signup and view all the answers

Why is it important to consider protein orientation during imaging?

To improve the resolution of the image Signup and view all the answers

What type of detector is used in cryo-electron tomography?

Direct electron detector Signup and view all the answers

What is a benefit of using cryo-electron tomography in understanding macromolecular structures?

Mapping the structure probability within the cell Signup and view all the answers

What is a characteristic of the interactive landscape in cells?

It is dynamic and interconnected Signup and view all the answers

What is the purpose of using a focused beam of gallium ions in Cryo-FIB milling?

To thin the vitrified sample by removing surface atoms Signup and view all the answers

Why is Cryo-FIB thinning preferred over mechanical sectioning at cryo-temperatures?

It avoids intrinsic cutting artifacts Signup and view all the answers

What problem might arise from the predetermined orientation of regions of interest in vitrified whole organisms like C.elegans?

Orientation may interfere with data collection Signup and view all the answers

What role does reorientation of lamella play in addressing data completeness problems?

It provides access to previously obscured regions Signup and view all the answers

What issue might arise from the arrangement of cellular structures on grids?

Interference with analysis due to similar orientation Signup and view all the answers

What is the function of a platinum coating in Cryo-FIB milling?

To provide structural support during ion beam milling Signup and view all the answers

Which molecular structure is visualized at the highest resolution using cryo-ET according to the provided data?

dNTPase Signup and view all the answers

What is the primary reason for using high pressure freezing (HPF) for samples thicker than 10 µm?

To reduce crystalline ice formation Signup and view all the answers

Which publication discusses the identification of a novel RNAP-ribosome supercomplex?

Cell, 183 (3): 730-738.e13 (2020) Signup and view all the answers

What is the resolution of the Influenza A matrix protein M1 as visualized by cryo-ET?

8.0 Å Signup and view all the answers

What is the expected outcome if crystalline ice forms during plunge freezing?

Damage to the native sample Signup and view all the answers

Which macromolecular structure has a resolution of 7.7 Å as determined by cryo-ET?

Clathrin/AP2 coat assembled on mem. Signup and view all the answers

Which factor is essential to avoid sample damage while preparing thick samples for cryo-ET?

Ensuring high cooling rate Signup and view all the answers

What is the resolution disparity between the SARS-CoV-2 spike glycoprotein and the Reovirus SLP?

1.7 Å Signup and view all the answers