Download MendeleyClassification of a Haemophilus influenzae ABC Transporter HI1470/71 through Its Cognate Molybdate Periplasmic Binding Protein, MolA.
Tirado-Lee, L., Lee, A., Rees, D.C., Pinkett, H.W.(2011) Structure 19: 1701-1710
- PubMed: 22078568
- DOI: https://doi.org/10.1016/j.str.2011.10.004
- Primary Citation of Related Structures:
3PSA, 3PSH - PubMed Abstract:
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.
Organizational Affiliation:
Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
