I'm Steve Harvey from the school
of biology a Georgia Tech.

I'm a computational structural biologist.

So my research research group uses
a variety of computational methods

to study structure function
relationships in macromolecules

we collaborate with both theoreticians and
experimentalists as well and all of this.

Now many of you will be familiar with what
a molecular model is this is a model of

a protein alpha helix.

Showing all of the atoms
in the hydrogen bonds.

We work with models at the atomic level.

We also work with models
that lower resolution.

So this is a model of a virus
that was developed in my group.

This is the our in a component of an
R.N.A. virus the genome which lies inside

the protein caps and and I'll show you
more on this structure in a moment.

We work at even her lower resolution.

To model very large systems you have
to surrender some of the atomic detail.

So this is a very very low resolution
model of a piece of D.N.A. D.N.A.

is basically an elastic material and
that as a matter of fact this piece of

foam has elastic properties that scale
very similarly to those of D.N.A.

This is about one K.B.
one thousand base pairs of D.N.A..

Of course in this model what's missing
are the Electra static interactions that

are very important in
the structure of D.N.A.

itself in our computer models
of course we include those.

The last physical model I'm going to show
you is a model of the right business

which is the.

The micro molecular assembly at
which protein synthesis takes place

the messenger R.N.A. and T.

Arnie's passed between the two
subunits a large subunit which

catalyzes the formation of the peptide
bond and the small subunit which is known

to examine the fidelity of the interaction
between the T.R.T. and the M.R. name.

Now this model.

Shows what we knew about the ride his own
in the late one nine hundred seventy S.

This was all we had was the shape.

Today because of great advances in
experiment particularly the success

of the X. ray crystallographer is
in crystallizing both the large and

the small subunits and
now intact right is ohms.

And also because of the contributions
of cryo we elect Tron microscopy

we have a very detailed pictures
of the right his own and

my first slide shows the work that
we do on the right of his own.

On the left is a schematic
of a kinetic scheme.

We're got by Marina Rodnina and
her colleagues in Germany and

on the right is a picture of the model
of the small subunit of the right of his

own this is done in collaboration with
European Frank now at Columbia University

and the outline of that is
the detailed cryo electron microscopy

picture of the small five unit today and
the red in the blue represent the R.N.A.

and the protein modeled in all
atom detail in that map and from

the very subtle changes in confirmation
that you see in the Crowley electron

microscope as the ride his own passes
from one stage to another in translation.

We attempt to infer the details of the
structural changes at the atomic level.

We also have a large effort on viruses and

this slide shows on the left
microgram a micrograph of a.

Bacteria phages a virus
which infects bacteria

the bacterium is the quarter of
a sphere you see on the lower left and

of course the bacteria phages
itself sits up on the right.

Bay on the right hand picture you see what
a bacteria phage is basically a virus

is a protein coat surrounding
a genome in this case the D.N.A.

double T. tickle genome which is stored
in the head and then on infection.

As you see at the very low or
right is injected into the host cell.

We are not studying injection alone we are
also studying the packaging of the D.N.A.

in two viruses and on the left the four
the three figures on the left are for

show some of our work on the models for
double he the D.N.A.

being packaged inside bacteria
phages we represent these

in different ways depending on what kind
of a message we're trying to convey or

what type of information we're trying
to extract from the models and

then of course we quantify
them on the bottom the.

Slide shows the force as a function
of the fraction of the D.N.A.

that is packaged the red curve is
an experiment from Carlos Bustamante his

lab at Berkeley and the black dots
represent data from my own laboratory.

And on the right.

You see three images from top to bottom
bottom showing a model we have developed

for the assembly of R.N.A.
viruses small are in a viruses

the protein caps it does not
assemble until the Arnie is present.

This is different than the D.N.A.
bacteria phage where the protein core is

necessary part of the protein caps and
forms first and the D.N.A. is injected.

This model was done in
collaboration with Jack Johnson and

in Edison a man at the Scripps Institute.

In California.

And I'm going to finish
by showing you a movie.

That we have developed that
shows the packaging process in

this particular virus the image you have
on the left now is the final structure and

the movie will demonstrate for you the
actual procedure so I'll just let it run

the D.N.A. double helix that elastic
model a showed you is represented in our

computer models by a chain of beans the
little red balls each of those beads are.

Presents approximately six base
pairs of the D.N.A. The D.N.A.

is injected into a capsule and we're not
showing the cap's ID in the picture here.

The D.N.A. is colored red orange yellow
and so on the first ten percent.

The second ten percent.

And so on as it comes into the capsule.

And by examining these movies and by
a careful quantitative analysis of them.

We are able to infer quite a bit
about the packaging process both

the thermodynamics the kinetics and
the structural aspects.

Thank you very much.