The invention relates to a gear rack arrangement, which, for the compensation of backlash, comprises two gear racks which are mutually displaceable on latch elements and are resiliently braced, and refers both to the assembly and disassembly characteristics of the gear rack arrangement and to the number of moulded elements used. A method is implemented in a computer infrastructure having programming instructions. The raw materials of the present invention are readily available from the rural areas, and the molding is carried out at a temperature of 100-300 degrees C. The invention further relates to screening methods for identifying agonists and antagonists of the polynucleotides and polypeptides of the present invention.