Functional Determinants of Metal Ion Transport and Selectivity in Paralogous Cation Diffusion Facilitator Transporters CzcD and MntE in Streptococcus pneumoniae.

ABSTRACT:

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Cation diffusion facilitators (CDFs) are a large family of divalent metal transporters that collectively possess broad metal specificity and contribute to intracellular metal homeostasis and virulence in bacterial pathogens. Streptococcus pneumoniae expresses two homologous CDF efflux transporters, MntE and CzcD. Cells lacking mntE or czcD are sensitive to manganese (Mn) or zinc (Zn) toxicity, respectively, and specifically accumulate Mn or Zn, respectively, thus suggesting that MntE selectively transports Mn, while CzcD transports Zn. Here, we probe the origin of this metal specificity using a phenotypic growth analysis of pneumococcal variants. Structural homology to Escherichia coli YiiP predicts that both MntE and CzcD are dimeric and each protomer harbors four pairs

SUBMITTER: Martin JE 

PROVIDER: S-EPMC4800876 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature