Organisms express metal-binding proteins in order to deal with essential metal ions that can be potentially toxic. A common trend of bacterial metal homeostasis pathways is the presence of a GTPase, and several of these proteins are members of the G3E family of P-loop GTPases. In this work we focused on E. coli YeiR, member of the under-characterized COG0523 subfamily, and on M. thermoacetica AcsF. The in vitro metal-binding properties of isolated YeiR are presented. The protein binds Ni2+ and Zn2+ with low micromolar affinity, and oligomerizes in the presence of metal. The GTPase activity of YeiR is similar to that measured for other members of the group and is enhanced by Zn2+. In the case of AcsF, it was not possible to establish concluding evidence that the protein binds metal. This study helps shed light upon members of the under-characterized subfamily of G3E P-loop GTPases.

Organisms express metal-binding proteins in order to deal with essential metal ions that can be potentially toxic. A common trend of bacterial metal homeostasis pathways is the presence of a GTPase, and several of these proteins are members of the G3E family of P-loop GTPases. In this work we focused on E. coli YeiR, member of the under-characterized COG0523 subfamily, and on M. thermoacetica AcsF. The in vitro metal-binding properties of isolated YeiR are presented. The protein binds Ni2+ and Zn2+ with low micromolar affinity, and oligomerizes in the presence of metal. The GTPase activity of YeiR is similar to that measured for other members of the group and is enhanced by Zn2+. In the case of AcsF, it was not possible to establish concluding evidence that the protein binds metal. This study helps shed light upon members of the under-characterized subfamily of G3E P-loop GTPases.