Tags: Biological Database, Database.
SHIFTCOR (Shift Correction) is a freely available web server as well as a stand-alone computer program for protein chemical shift re-referencing. Chemical shift referencing is a particularly widespread problem in biomolecular NMR with up to 25% of existing NMR chemical shift assignments being improperly referenced. Some of these referencing problems can lead to systematic errors of between 1.0 to 2.5 ppm (especially in 13C and 15N chemical shifts).