Insights into the mode of action of a putative zinc transporter CzrB in Thermus thermophilus.

ABSTRACT: The crystal structures of the cytoplasmic domain of the putative zinc transporter CzrB in the apo and zinc-bound forms reported herein are consistent with the protein functioning in vivo as a homodimer. NMR, X-ray scattering, and size-exclusion chromatography provide support for dimer formation. Full-length variants of CzrB in the apo and zinc-loaded states were generated by homology modeling with the Zn2+/H+ antiporter YiiP. The model suggests a way in which zinc binding to the cytoplasmic fragment creates a docking site to which a metallochaperone can bind for delivery and transport of its zinc cargo. Because the cytoplasmic domain may exist in the cell as an independent, soluble protein, a proposal is advanced that it functions as a metallochaperone and that it regulates the zinc-transp

SUBMITTER: Cherezov V 

PROVIDER: S-EPMC2614558 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature