November 20, 2023 Fromme, P., P. Gräber, and J. Salnikow, (1987) Isolation and identification of a fourth subunit in the membrane part of the chloroplast ATP-synthase. FEBS letters, 218(1): 27-30. Home » Fromme, P., P. Gräber, and J. Salnikow, (1987) Isolation and identification of a fourth subunit in the membrane part of the chloroplast ATP-synthase. FEBS letters, 218(1): 27-30.