[1] Univ Bielefeld, Ctr Biotechnol CeBiTec, D-33594 Bielefeld, Germany
[2] Univ Bielefeld, Lehrstuhl Genet, Fak Biol, D-33594 Bielefeld, Germany
[3] Max Planck Inst Biochem, Abt Membranbiochem, D-82152 Martinsried, Germany
[4] Max Planck Inst Entwicklungsbiol, D-72076 Tubingen, Germany
[5] Univ Bielefeld, Tech Fak, D-33594 Bielefeld, Germany