2.A.4.7.10 Cobalt/zinc resistance protein B, CzrB, of 291 aas and 6 TMSs. It has a cytosolic extramembranal C-terminus. This 92-residue
fragment may function independently of the full-length integral membrane
protein. X-ray analyses of this fragment to 2.2 A resolution with and 1.7 A without zinc
ions have been solved. The former has at least two zinc ions bound per monomer (Höfer et al. 2007). 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 zinc. A proposal was advanced that it functions as a
metallochaperone and regulates the zinc-transporting activity of
the full-length protein. The latter requires that zinc binding becomes
uncoupled from the creation of a metallochaperone-docking site on CzrB (Cherezov et al. 2008).
|
Accession Number: | Q8VLX7 |
Protein Name: | CzrB protein |
Length: | 291 |
Molecular Weight: | 31234.00 |
Species: | Thermus thermophilus [274] |
Number of TMSs: | 6 |
Substrate |
cobalt(2+), zinc(2+) |
---|
1: MAEGAARLSL VVALLVLGLK AFAYLLTGSV ALLSDALESL VNVAAALAAL LALRVARKPP
61: DQNHPFGHTK AEYVSAVLEG VLVVLAALWI AREALPRLLH PVPLEGLGLG LGVSLLASLL
121: NGLLAYHLLK EGRRHRSPAL TADGYHVLSD VLTSLGVVLG VGLAGLTGLW VLDPLLALAV
181: AGQILFLGYR IVRESVGGLM DEGLPPEEVE RIRAFLQERI RGRALEVHDL KTRRAGPRSF
241: LEFHLVVRGD TPVEEAHRLC DELERALAQA FPGLQATIHV EPEGERKRTN P