These proteins include mannose-specific lectins from plants[1] as well as bacteriocins from bacteria [2].

1: The 2.0 A structure of a cross-linked complex between snowdrop lectin and a branched mannopentaose: evidence for two unique binding modes. Wright CS, Hester G; Structure 1996;4:1339-1352. PMID:8939757

2: Plant lectin-like bacteriocin from a rhizosphere-colonizing Pseudomonas isolate. Parret AH, Schoofs G, Proost P, De Mot R; J Bacteriol 2003;185:897-908. PMID:12533465