Puzzle 1315, segment 129 (?)

Started by gitwut

gitwut Lv 1

Why is there a segment (or ghost of segment) 129 floating around in puzzle 1315? Could it be causing part of the problem people are having? See attached image.

LociOiling Lv 1

Looks like you found the copper ion that's supposed to be located in the density. It's pretty well hidden, I was looking for it, but not seeing it. I finally had to turn off the density and switch to a light background to see it. Segment 129 has secondary structure type "M" (for "molecule"), making it a normal ligand. Many recipes will detect this type of ligand, and avoid working on it.

The puzzle comments say:

This structure also contains a copper ion, which has been already been placed in the density for you. Three residues are known to interact with this copper ion: HIS 46, CYS 112, and HIS 117.

So it might be possible to see the two histidines near the ion.

bkoep Staff Lv 1

That's correct. Segment 129 is the copper ion, which is supposed to be placed within the density cloud. Most, if not all, of the crashes in puzzle 1315 result from a problem with this copper atom. I'm not sure why you're seeing the copper ion at a position distant from the density cloud. gitwut, did you load a saved solution or restart the puzzle before taking this screenshot?

gitwut Lv 1

bkoep,

No restarts or saved loads. I cut the SS up, placed them, used shake, wiggle and the tool to center it within the density cloud. It was then that I noticed segment 129 in the background. The script Loop explorer 3.01 detects segment 129 and wouldn't run correctly unless I specified segment ranges that excluded it (by default, it selects segment 1 through 129).