Transports the metallophore pseudopaline, which is involved in the acquisition of nickel and zinc, and thus enables bacterial growth inside the host, where metal access is limited. Is probably involved in the import of pseudopaline-metal complexes. Is part of the operon cntOLMI that is negatively regulated by zinc level through the Zur repressor, which leads to transcriptional activation of this operon under zinc depletion (PubMed:28898501). Highly induced in response to airway mucus secretions (AMS) treatment (PubMed:26446565). Deletion mutant does not show growth defect in LB medium, but it exhibits an evident growth defect after treatment with AMS. Belongs to the TonB-dependent receptor family.