DAPPLE 2 allows you to identify PTM sites using data for 19 different post-translational modifications (PTMs) from 16 different online databases. The PTMs you have to choose from, along with the databases from which the data are derived, are listed below. Also indicated is the number of PTM sites from each database. To visit the website for a particular database, click on the name of that database.

PTM	Database	Number of sites	Original number of sites before filtering
Acetylation
	ASEB	4,346	4,592
	CPLM	46,453	58,563
	dbPTM	9,295	16,524
	N-Ace	1,215	1,521
	PHOSIDA	3,445	3,446
	PhosphoSitePlus	30,222	31,484
	All databases combined (unique)	70,650	-
Butyrylation
	CPLM	39	39
Carboxylation
	dbPTM	232	425
Crotonylation
	CPLM	58	58
Glycation
	CPLM	315	323
	GlycateBase	70	70
	All databases combined (unique)	349	-
Glycosylation
	dbPTM	7,641	21,236
	PHOSIDA	5,463	5,531
	All databases combined (unique)	12,576	-
	Malonylation
CPLM		32	35
Myristoylation
	dbPTM	148	205
Methylation
	CPLM	928	1,144
	dbPTM	1,005	2,205
	PhosphoSitePlus	7,981	9,509
	All databases combined (unique)	8,724	-
Nitrosylation
	dbPTM	3,012	3,241
	dbSNO	4,020	4,165
	All databases combined (unique)	4,050	-
O-β-GlcNAcylation
	dbPTM	607	681
Palmitoylation
	dbPTM	237	348
Prenylation
	dbPTM	127	169
Phosphoglycerylation
	CPLM	136	140
Phosphorylation
	dbPTM	147,943	284,117
	P3DB	28,603	39,205
	PHOSIDA	61,925	75,813
	PhosPhAt	9,139	23,963
	Phospho.ELM	35,631	54,821
	PhosphoGRID	20,022	20,057
	PhosphoPOINT	10,300	15,746
	PhosphoSitePlus	273,326	292,915
	All databases combined (unique)	379,247	-
Propionylation
	CPLM	49	53
Succinylation
	CPLM	2,417	2,558
Sulfation
	dbPTM	114	182
Sumoylation
	CPLM	868	928
	dbPTM	781	1,029
	PhosphoSitePlus	815	870
	All databases combined (unique)	1,305	-
Ubiquitination
CPLM	127,632	139,951
dbPTM	23,200	23,930
mUbiSiDa	48,810	48,810
PhosphoSitePlus	60,341	62,450
UbiProt	185	211
All databases combined (unique)	149,689	-