protein-glutamic acid ligase activity, elongating
Catalytic reaction :(L-glutamyl)n-L-gamma-glutamyl-L-glutamyl-[protein] + ATP + L-glutamate = (L-glutamyl)n+1-L-gamma-glutamyl-L-glutamyl-[protein] + ADP + H+ + phosphate.
GO:0070739
protein-glutamic acid ligase activity
is_a