Structure of an engineered β-lactamase maltose binding protein fusion protein: insights into heterotropic allosteric regulation.

ABSTRACT: Engineering novel allostery into existing proteins is a challenging endeavor to obtain novel sensors, therapeutic proteins, or modulate metabolic and cellular processes. The RG13 protein achieves such allostery by inserting a circularly permuted TEM-1 β-lactamase gene into the maltose binding protein (MBP). RG13 is positively regulated by maltose yet is, serendipitously, inhibited by Zn(2+) at low µM concentration. To probe the structure and allostery of RG13, we crystallized RG13 in the presence of mM Zn(2+) concentration and determined its structure. The structure reveals that the MBP and TEM-1 domains are in close proximity connected via two linkers and a zinc ion bridging both domains. By bridging both TEM-1 and MBP, Zn(2+) acts to "twist tie" the linkers thereby partially dislodging a

SUBMITTER: Ke W 

PROVIDER: S-EPMC3375305 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature