FIGURE 2.

Structure prediction of the b-dimers. Paircoil2 (74) was used to determine the propensity of the b-sequences shown in Fig. 1 to be part of heptad sequences, a prerequisite for the formation of left-handed coiled-coil packing interactions. A P-score is given to each individual amino acid by the program that defines the probability of this amino acid to reside at a certain position within a heptad. A P-score lower than 0.03 (black horizontal line) indicates a very high probability of amino acids being at heptad positions. The red line indicates the P-scores for E. coli subunit b, and the blue line shows the P-scores for the b-subunit of the cyanobacterium Synechocystis sp. PCC 6803, which we also study in our lab group.