α-Carboxysome Size Is Controlled by the Disordered Scaffold Protein CsoS2
Not Available
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Engineering topics
Chaijarasphong, Thawatchai
Publications and source records attributed to Chaijarasphong, Thawatchai.
Multivalent interactions between CsoS2 and Rubisco mediate α-carboxysome formation
Carboxysomes are bacterial microcompartments that function as the centerpiece of the bacterial CO 2 -concentrating mechanism by facilitating high CO 2 concentrations near the carboxylase Rubisco. The carboxysome self-assembles from thousands of individual proteins into icosahedral-like particles with a dense enzyme cargo encapsulated within a proteinaceous shell. In the case of the α-carboxysome, there is little molecular insight into protein–protein interactions that drive the assembly process. In this work, studies on the α-carboxysome from Halothiobacillus neapolitanus demonstrate that Rubisco interacts with the N terminus of CsoS2, a multivalent, intrinsically disordered protein. X-ray structural analysis of the CsoS2 interaction motif bound to Rubisco reveals a series of conserved electrostatic interactions that are only made with properly assembled hexadecameric Rubisco. Although biophysical measurements indicate that this single interaction is weak, its implicit multivalency induces high-affinity binding through avidity. Taken together, our results indicate that CsoS2 acts as an interaction hub to condense Rubisco and enable efficient α-carboxysome formation.
59 BASIC BIOLOGICAL SCIENCES↗