i find that this sort of puzzle as the 425 are not easy to see because all is grey. Even if i change the view, it isn't easy to see the segments to mutate. It is because you want that to be more difficult or because it is the best way to show this puzzle? If not, and if some others people are agree with me, isn't possible to let the segments to change in green as the other's ones?

Sorry if my question is stupid.....

Scripts were kindly provided by FoldeRNA and AD to set the aa sequence. There was apparently a difference of 12 segments between the two scripts, which may be of interest.
Neither script provided majic results unless presumably your position matched one of theirs.
Out of curiosity I ran some basic tests.

Test one - from a reset puzzle state, no other changes; I ran each script:
FoldeRNA AD Foldit mutate button at CI =1
12982 12393 13036

From a resët puzzle after Blue Fuze for stabilisation I ran the scripts (using the same saved solution after fuze), then ravs repeat fuzes and 8 loops of compressor

FoldeRNA AD Foldit mutate button at CI =1
12970 12709 13087

The AD sequence did seem to have more wriggle room.

So very unlike the previous puzzle where Marie's aa sequence added points, probably because the position was more restricted.

So it is all about the position in this one although the position was still very restrained.
Of course the method may be incorrect however I restrained myself to using public scripts without any manual movements, so perhaps a different starting stabiliser and post mutate scripts may have made a big difference.

Hat tips to AD team, especially tyggy and tyler for helping to clue me into the Move Tool (aka purple pointy compass rose) that makes games like this almost enjoyable.

Have a look at Tutorial Puzzle 4-5, "Moving Along" and its wiki hint (scroll down)
http://foldit.wikia.com/wiki/Tutorial_Puzzles#Hydrophobics_and_Hydrophilics

Having spent many hours banding, wiggling and praying these design ligands into position it was a blessed relief to realize you can move and rotate the whole ligand as follows:

with ligand in pull mode ...
http://fold.it/portal/files/chatimg/irc_235191_1307977546.png

... left-click on the backbone of the ligand to bring up the purple pointy Move Tool.
http://fold.it/portal/files/chatimg/irc_235191_1307977652.png

Now left-click and drag on the Move Tool to rotate the ligand in place.
http://fold.it/portal/files/chatimg/irc_235191_1307977722.png

Right-click and drag on the Move Tool will move the ligand around in the plane of the screen ...
http://fold.it/portal/files/chatimg/irc_235191_1307977823.png

... and, my favourite, shift-click and drag on the Move Tool to draw the ligand toward you or push it away.
http://fold.it/portal/files/chatimg/irc_235191_1307977910.png

http://www.bbc.co.uk/news/health-14324901

Wanted to mention it since it's related and interesting.