Figure 2.

Schematic representation of the assembly of the Anabaena and the Escherichia coli RNA degradosome. (A) Anabaena RNA degradosome; (B) Escherichia coli RNA degradosome. RNase E forms tetramers; here, only one of them (in green) is shown for simplicity. The components of the degradosome are shown relative to the positions of the RNase E proteins. Four conserved subregions (C1, C2, C3 and C4) and three variable subregions (V1, V2 and V3) have been identified in the noncatalytic region of Anabaena RNase E ³⁵ . Note that the E. coli RNase E catalytic region is composed of a large domain that is equivalent to the catalytic region of Anabaena RNase E and a small domain that has no counterpart in Anabaena RNase E.