3PSA : Classification of a Haemophilus influenzae ABC transporter HI1470/71 through its cognate molybdate periplasmic binding protein MolA (MolA bound to tungstate)

  • Leidamarie Tirado-Lee (Contributor)
  • A. T. Lee (Contributor)
  • D. C. Rees (Contributor)
  • Heather W Pinkett (Contributor)



Experimental Technique/Method:X-RAY DIFFRACTION
Classification:METAL TRANSPORT
Release Date:2011-11-30
Deposition Date:2010-12-01
Revision Date:2017-11-08
Molecular Weight:36890.77
Macromolecule Type:Protein
Residue Count:326
Atom Site Count:2588

molA (HI1472) from H. influenzae encodes a periplasmic binding protein (PBP) that delivers substrate to the ABC transporter MolB(2)C(2) (formerly HI1470/71). The structures of MolA with molybdate and tungstate in the binding pocket were solved to 1.6 and 1.7 Å resolution, respectively. The MolA-binding protein binds molybdate and tungstate, but not other oxyanions such as sulfate and phosphate, making it the first class III molybdate-binding protein structurally solved. The ∼100 μM binding affinity for tungstate and molybdate is significantly lower than observed for the class II ModA molybdate-binding proteins that have nanomolar to low micromolar affinity for molybdate. The presence of two molybdate loci in H. influenzae suggests multiple transport systems for one substrate, with molABC constituting a low-affinity molybdate locus.
Date made available2011

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