SAN FRANCISCO - A Christian legal group has filed a lawsuit to overturn a first-of-its-kind California law that prohibits licensed mental health professionals from practicing therapies aimed at making gay and lesbian teenagers straight.

The Pacific Justice Institute challenged the law signed Saturday by Gov. Jerry Brown. The lawsuit was filed late Monday in U.S. District Court in Sacramento.  

The institute filed the suit on behalf of a psychiatrist and a marriage and family therapist who is also a church pastor in San Diego. It also names as a plaintiff Aaron Bitzer, a Culver City man who said he has benefited from "reparative" therapy.

The lawsuit claims the law, which is scheduled to take effect Jan. 1, violates First Amendment and equal protection rights.