Sheet flattening techniques

Sheet Flattening Techniques

Sheet flattening is an effective technique which can gain you many points. Here are three techniques which may improve your score.

Note: Keep in mind that when you wiggle/shake out any change, from rebuilds to tweaking, adjusting the clashes manually may result in a higher gain than you would have by simply using the plain wiggle/shake buttons.

Note: You may wish to group the strands together with bands before flattening them.

I: Pull While Rebuilding Sheet

Rebuild with Pull

One way to flatten a sheet is to place bands at both ends and pull it flat. After bands are placed at both ends, rebuild is used to let the sheet find new positions as the bands pull. The pulling bands will cause the rebuild to favor straighter sheet positions. Remember, when trying to flatten a sheet, the sheet has to have room to expand. If adjacent structures or sections are too close, clashes may occur causing unsatisfactory results. A remedy for this is to set the clashing importance very low. This makes it easier to manipulate the sheets into a more desirable position without disturbing the remainder of the protein.

Steps:

1. Select strand
2. Decide the plane where you want to straighten out the strand (i.e. a line)
3. Place band(s) on the first segment of strand. Other end of band(s) should be in the general direction of the plane in step 2.
4. Place bands(s) on the last segment of strand. Other end of band(s) should be in the general direction of the plane in step 2
5. (optional) Set band strength (for recipes, use http://fold.it/portal/recipe/7489 or http://fold.it/portal/recipe/29188)
6. (optional) Lower the clashing importance
7. Right-click anywhere on strand and select Rebuild
8. Watch carefully and you will see the strand straightening
9. Stop when desired
10. Delete bands
11. (optional) Reset clashing importance back to 1.00
12. Wiggle/Shake out with Clashing at 1.00 or use your favorite fuse script/technique

NOTE: For steps 3 and 4, you may choose to place the band(s) on the segments just outside the strand. Typically, these are loop segments. Some players have found this provides additional room for the rebuild process.

II: Tweaking

The Tweak Tool

There is also the Tweak tool STRAIGHTEN option in foldit (see image to the right). This is a pretty comprehensive set of tools, which can untwist AND straighten sheets at the same time! The "Pull-While-Rebuilding" approach, discussed earlier, might be more useful in situations where you want to leave twists in place, even though you will usually want to straighten the sheet. In situations where a rebuild or sheet tweaking doesn't work, you'll sometimes want to become imaginative...

Steps:

1. Select Strand
2. (optional) Set the Clashing Importance to be lower: Behavior, Clashing Importance
3. Right-click anywhere on strand, Tweak
4. Mouse to purple knob with mouse-over hovertip of "Straighten out structure"
5. Hold down mouse button
6. Watch - you will see the strand straightening
7. Stop when desired
8. (optional) Reset Clashing Importance back to 1.00
9. Wiggle/Shake out with Clashing at 1.00 or your favorite fuse script/technique

III: Using CHANGE BAND LENGTH to Push Apart Ends of Sheet

Connecting first segment with last segment in a strand

After right-click on rubber band

Adjusting band length

Band length set to 20 (beyond strand ends)

Pulling on opposite ends of the sheet to straighten it also works as another technique. Put a band from the first segment of the sheet to the last segment of the same sheet and increase the band distance.

In that way, the band acts to "push" the two ends apart and straightens the sheet in the process. How will you know that the band is longer than the sheet? It will stick out but with a thinner section - like a needle. You will see a band underneath that looks like a double arrow. :) First, apply the band between the first and last segments of the sheet. Next, lengthen the band beyond the length of the sheet. Finally, wiggle the sheet.

Steps:

1. Select strand
2. (optional) Set the Clashing Importance to be lower: Behavior, Clashing Importance
3. Click-drag from first to last segment of sheet
4. Verify rubber band connects first to last segment correctly (see second picture)
5. Right-click on rubber band, Change Band Length to larger value (e.g. 20)
6. Verify arrows are on outside (beyond the strand) (see fourth picture)
7. (optional) Set band strength (for recipes, use http://fold.it/portal/recipe/7489 or http://fold.it/portal/recipe/29188)
8. Right-click on strand, Wiggle
9. Watch - you will see the strand straightening
10. Stop when desired
11. (optional) Reset Clashing Importance back to 1.00
12. Wiggle/Shake out with Clashing at 1.00 or your favorite fuse script/technique