A Trap-Door Mechanism for Zinc Acquisition by Streptococcus pneumoniae AdcA.

ABSTRACT: Zinc is an essential element in all domains of life. Nonetheless, how prokaryotes achieve selective acquisition of zinc from the extracellular environment remains poorly understood. Here, we elucidate a novel mechanism for zinc-binding in AdcA, a solute-binding protein of Streptococcus pneumoniae Crystal structure analyses reveal the two-domain organization of the protein and show that only the N-terminal domain (AdcA_N) is necessary for zinc import. Zinc binding induces only minor changes in the global protein conformation of AdcA and stabilizes a highly mobile loop within the AdcA_N domain. This loop region, which is conserved in zinc-specific solute-binding proteins, facilitates closure of the AdcA_N binding site and is crucial for zinc acquisition.

SUBMITTER: Luo Z 

PROVIDER: S-EPMC7858048 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature