Any process that modulates the frequency, rate or extent of ubiquitin ligase activity, the catalysis of the reaction: ATP + ubiquitin + protein lysine = AMP + diphosphate + protein N-ubiquityllysine.
Any process that modulates the frequency, rate or extent of ubiquitin ligase activity, the catalysis of the reaction: ATP + ubiquitin + protein lysine = AMP + diphosphate + protein N-ubiquityllysine.