FtsW is a peptidoglycan polymerase that is functional only in complex with its cognate penicillin-binding protein.
Taguchi A, Welsh MA, Marmont LS, Lee W, Sjodt M, Kruse AC, Kahne D, Bernhardt TG, Walker S. Nat Microbiol. 2019 Apr; 4(4):587-594. Epub 2019 Jan 28.