"Who is the prosecutor?"
Translation:Quem é o promotor?
It usually works the same way as in English. I always saw it as intuitive, but now that I think of it there are patterns when it comes to keeping parts of the sentence in a logical order. In "what time is it", the elements are just the verb and the subject ("x time" + to be), but in "who is the prosecutor", the last word is a subject complement (x + to be + s. c.), so the structure is different there and therefore different rules apply. In the first structure, the elements switch places if it's a question or an answer, but in the second structure you can just fill the hole with "who", I think. Correct me if I'm wrong though! Just speculating.