Novel families containing Dx[DN]xDG calcium-binding loops.

aA version that includes previously reported families is provided as Table S1.bAll these proteins have been experimentally demonstrated to bind calcium ions.cAs defined by Pfam, SMART or by full-length matches in PSI-BLAST (E-value of 0.0001) run until convergence.dProteins from UniRef90 with e-valueMethods for details.eBased on the entry for a homologous protein or the authors' description.fThe motif commencing residue 233 is not bound to calcium in the deposited structure but crystal soak data show that it is capable of doing so [26].gA distinct group could not be defined with PSI-BLAST.