Table 7.

Class-wise statistics on the number of enzyme sequences, and the subclasses at each level.

EC Level-1(6 Classes) (Example:1.x.x.x)	Total Sequences	Subclasses at EC Level-2 (example:1.1.x.x)	Subclasses at EC Level-3 (example:1.1.1.x)	Subclasses at EC Level-4 (example:1.1.1.1)
EC1: Oxidoreductases	8662	22	90	658
EC2: Transferases	23604	9	31	751
EC3: Hydrolases	15183	11	49	781
EC4: Lyases	5525	7	15	268
EC5: Isomerases	4146	6	17	127
EC6: Ligases	7830	6	11	109
Total	64950	61	213	2693

There are 6 major classes at Level-1 that expand into 61, 213 and 2,693 subclasses at Levels 2, 3 and 4, respectively.