Name: 10. Protein Folding 3
Uploaded: 2020-03-29T16:17:19.000Z
Duration: 46 min 14 s
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Basic passive voice

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ELIZABETH NOLAN: We're going to move on with GroEL/GroES

and a few more comments about where we closed yesterday

Has anyone stuck trigger factor or GroEL into PubMed

Yeah, so Rebecca's question yesterday, or on Monday,

about trigger factor and active versus passive folding

put trigger factor in PubMed, as of last night,

GroEL is closer to 2,000 to 3,000-- in that range.

If you put trigger factor active folding,

Most of those are about using trigger factor

So if you also express trigger factor, does that help?

And it looked like there was one paper in those 34

that suggests an active folding role for one of the domains.

And so, the point there is there are many, many studies that

consider these chaperones and a huge literature to search.

So what we're able to cover here is really just the tip

There's also a new review out on GroEL/GroES,

So it just came out last month, and I really

of talking about current questions that are unanswered

yet in terms of models and presenting different models

for how this folding chamber works-- so passive

And they also give a summary of the substrate scope--

so the experiment we'll talk about today.

went over the structure of this folding chamber

and here's just another depiction of the overview.

So effectively, we have to back-to-back heptamer rings

Some polypeptide in its non-native state can bind.

It initially binds up at the top by these apical domains,

and there are some hydrophobic interactions.

OK, ATP also binds, and we have all seven ATPs

found within one ring, the ring that has the polypeptide.

OK, we see the lid come on, and then this polypeptide

has some time, a residency time, in this chamber to fold.

which is generally quoted on the order of 6 to 10 seconds,

And during that time, the ATPs are hydrolyzed.

So somehow, this ATP hydrolysis gives conformational changes

So one point to make involved cooperativity,

so I hope you've all seen cooperativity before, probably

We have examples here of positive cooperativity

So within one heptamer ring, ATP binds to all seven subunits.

And then we can think about negative cooperativity

So the other heptamer ring will not have ATP bound here.

So what is happening inside this chamber?

and it's given this protected environment to fold.

And we saw that when the GroES lid comes in

that the hydrophilic nature, hydrophobic nature

So I just want to point out-- and this also builds upon

where the primary sequence dictates the trajectory?

Or does the actual chamber itself play a role?

And effectively, is there forced unfolding or refolding

And the cartoon that was just up indicated that to some degree.

And what I would say is that the pendulum on this

has swayed quite a bit over the years in terms of

Subtitles ListPlay Video

10. Protein Folding 3

immune

trigger

period

native