Assignment quality control

At the menu option M: Assignment: Quality Reports you can access a suite of analyses which generate automated reports about the quality and completeness of your assignments. The first tab {Atom Assign Status}, simply lists how many of each kind of residue and atom type you have resonance assignments for. The second tab {Through-Space Status}, shows statistics for how many NOE (and other through-space) connections you have across your molecular system.

While the first two tabs are dedicated to analysing completeness, the last two tabs are dedicated to finding mistakes and inconsistencies in assignments. These tables look at the same kind of issues, but one presents the information from a resonance point of view; {Resonances} , and the other from a peak point of view; {Peaks}. Most notably the assignments are checked for the following criteria:

• • An assignment to a given atom is duplicated.

  • The standard deviation for a chemical shift is large.

  • If a peak position is far from the chemical shift average (irrespective of the shift's deviation).

  • A resonance has an impossible number of covalently bound partners: e.g. an amide proton assigned to two HSQC peaks cannot be linked to both nitrogen resonances.

  • The chemical shift for an atom assignment is unlikely given the known chemical shift distributions (BMRB).

  • If peaks have unusual intensities or sign.

When something is potentially wrong, then cells of the tables are coloured red. A highlighted cell doesn't mean that something is definitely wrong, just that it warrants an explanation or further investigation. To find the peaks responsible for any aberration, simply click on the row in the table and click [Show Peaks]. In the resulting table you can assign or find any of the peaks in the various spectrum windows.

Previous: Structures