The functions of the different receptors in the transformation process are not fully understood. Once the neighboring cells recieve the cMP signal, they produce large amounts of cAMP and release it into the environment. Subsequently, they move towards the cell that initiated the signal. This method of signaling and movement brings the cells togther to form the slime mold. Knowledge of the three dimensional structure of the cAR2 receptor would aid in studies of the cAMP binding site, the slight conformational change produced once cAMP binds to the receptor, the receptor's association with the intracellular G protein, and the cascade of events that follow including the internal production of the cAMP and the initiation of movement.
G proteins are a subset of a superfamily of proteins that bind with guanine nucleotides.
These proteins are involved with protein synthesis and signal recognition as is the case for the cAMP signal of the starved Dictyostelium cells. Molecular Modelling Predicting three dimensional structure from the primary amino acid sequence is a difficult task yet a necessary one because not all protein structures have been determined by more rigorous methods including x-ray crystallography. Current methods of modeling include sequence homology , multiple alignments , prediction programs for secondary structure , solvent accessibility , transmembrane regions , and motifs . Based on these prediction results a template crystal structure can be chosen from the Brookhaven Protein Data Bank. PDB files are returned and the models are viewed with a program like Sybyl.