Inducibility of expression is a function of the promoter of the gene. By genetic manipulation, you can replace a constitutive promoter with an inducible promoter.
Adam is absolutely right. If you express the gene of your interest under a constitutive promoter the enzyme for which it is encoding would be expressed constitutively and will change from inducible to non-inducible.
By the way I am thinking, is there any probability the enzyme posttranslational interaction?
For example: COX-1 enzyme (if I am not mistaken i is considered as a constitutive enzyme)
Let's say I am interested to increase the production of prostanoids under COX-2 independent condition. I add substance A included coenzyme B and the concentration of interest is obtained.
Is it possible to have such approach beside manipulating the gene?