The capacity to engineer both the composition of compartments and their positioning advances synthetic biology into a new era, where the spatial context of cellular function (“where”) can be programmed as readily as its content (“what”).

This was a massive team effort. Congrats to all authors!

Without McdAB, CryoET shows large and disorganized aggregates of carboxysome components at the cell poles. By contrast, McdAB-expressing cells displayed fully assembled, properly sized, and unclustered carboxysomes distributed across the nucleoid region of the cell!

First, we showed that McdAB can distribute carboxysomes in E. coli!

Carboxysome organization is mediated by the Maintenance of Carboxysome Distribution (Mcd) system. McdB binds carboxysomes and induces McdA, a ParA-type ATPase, to oscillate along the nucleoid and distribute carboxysomes in the cell.

We set out to determine if this conserved evolutionary strategy across diverse bacteria and cargo-types can be used a blueprint for engineering a generalizable method for programming spatial control in bacteria.

The McdAB system spatially organize carboxysomes to promote efficient carbon fixation and ensure their equal inheritance during cell division. McdA, a ParA family ATPase, forms dynamic gradients on the nucleoid that position McdB-bound carboxysomes.