Vectors for producing polypeptides heterologous to prokaryotes are described comprising, along with the polypeptide-encoding nucleic acid, anti-termination nucleic acid that inhibits intragenic transcription termination with a non-lambda promoter therefor and/or nucleic acid encoding a GreA or GreB protein and a promoter therefor. Also described are processes for producing a heterologous polypeptide in prokaryotic host cells utilizing such elements to improve the quality and/or quantity of heterologous polypeptide produced.