{"cross_mech":[],"family":{"alphafold_models":1059,"candidate_reasons":["description_says_unknown_function","domain_of_unknown_function","pfam_previous_unknown_name"],"characterization_status":"","context_evidence_count":null,"cross_mech":{"example_proteins":0,"protein_traits_record":false,"records_by_mech":{},"scanned":false},"curation_status":"SEEDED","demotion_reasons":[],"description":"This entry represents XusB, a surface-exposed lipoprotein found exclusively in Bacteroidetes that functions in xenosiderophore acquisition. XusB adopts a unique seven-bladed beta-propeller fold with a deep, positively charged central calyx that binds enterobactin and other catecholate siderophores with high affinity (Kd = 148 nM for enterobactin) [[cite:PUB00162406]]. The protein is enriched in outer membrane vesicles (OMVs) and can be secreted into the extracellular milieu. XusB forms part of the xenosiderophore utilization system (xus operon: xusABC) in Bacteroides thetaiotaomicron, where it captures siderophores produced by other bacteria, particularly during iron-limiting conditions such as intestinal inflammation [[cite:PUB00162406],[cite:PUB00162407]]. XusB-bound enterobactin is shielded from sequestration by host lipocalin-2, thereby modifying nutritional immunity and potentially benefiting both commensal and pathogenic bacteria. The N-terminus contains a lipobox-like sequence with a conserved cysteine (typically at position 23) that is essential for membrane association, followed by a lipoprotein export signal (LES). Structural homologues are encoded by diverse Bacteroidetes species with conserved genetic synteny, though primary sequences are poorly conserved. This domain was previously annotated as DUF4374 (domain of unknown function 4374).","domain_architectures":4,"interpro_id":"IPR025401","known_evidence_count":null,"matches":1673,"name":"Xenosiderophore-binding lipoprotein XusB","partial_evidence_count":null,"pfam_id":"PF14298","proteins":1660,"proteomes":872,"short_name":"XusB","source_url":"https://www.ebi.ac.uk/interpro/api/entry/pfam/PF14298","structures":8,"taxa":1301,"unknown_status":"EX_DUF"},"inputs":{"cross_mech":"cross-mech-duf-examples-2026-10-10","members":"pfam-uniprot-uniref90-2026-10-07","protein_examples":"duf-protein-examples-2026-10-13","worklist":"interpro-pfam-duf-2026-10-10"},"members":[],"metadata":{"curation_status":"SEEDED","local_source":"source/data/families/PF14298.yaml","record":{"characterization_status":"UNSCORED","counters":{"alphafold_models":1059,"domain_architectures":4,"matches":1673,"proteins":1660,"proteomes":872,"structures":8,"taxa":1301},"curation_status":"SEEDED","description":"This entry represents XusB, a surface-exposed lipoprotein found exclusively in Bacteroidetes that functions in xenosiderophore acquisition. XusB adopts a unique seven-bladed beta-propeller fold with a deep, positively charged central calyx that binds enterobactin and other catecholate siderophores with high affinity (Kd = 148 nM for enterobactin) [[cite:PUB00162406]]. The protein is enriched in outer membrane vesicles (OMVs) and can be secreted into the extracellular milieu. XusB forms part of the xenosiderophore utilization system (xus operon: xusABC) in Bacteroides thetaiotaomicron, where it captures siderophores produced by other bacteria, particularly during iron-limiting conditions such as intestinal inflammation [[cite:PUB00162406],[cite:PUB00162407]]. XusB-bound enterobactin is shielded from sequestration by host lipocalin-2, thereby modifying nutritional immunity and potentially benefiting both commensal and pathogenic bacteria. The N-terminus contains a lipobox-like sequence with a conserved cysteine (typically at position 23) that is essential for membrane association, followed by a lipoprotein export signal (LES). Structural homologues are encoded by diverse Bacteroidetes species with conserved genetic synteny, though primary sequences are poorly conserved. This domain was previously annotated as DUF4374 (domain of unknown function 4374).","id":"Pfam:PF14298","interpro_id":"InterPro:IPR025401","name":"Xenosiderophore-binding lipoprotein XusB","pfam_id":"PF14298","provenance":{"generated_at":"2026-10-10T07:44:21.614711Z","path":"data/worklists/interpro-pfam-duf-2026-10-10.json","sha256":"17fb625876c9326ed284263a47bcd84e0d7844a31c040dc06cd2260c36f1c383","snapshot_id":"interpro-pfam-duf-2026-10-10","source_url":"https://www.ebi.ac.uk/interpro/api/entry/pfam/"},"seed_status":"EX_DUF","short_name":"XusB","source_url":"https://www.ebi.ac.uk/interpro/api/entry/pfam/PF14298"},"source":{"commit":"c8155abfcf881ad8662936343deb81e604e3a194","path":"data/families/PF14298.yaml","repository":"https://github.com/CultureBotAI/DUFMech","sha256":"3c39322929b6e04d7760539b23354e94a9a54aa0d3680c26996c4362a27a6c3e"}},"protein_examples":{"candidate_count":0,"discovery_scanned":true,"example_count":0,"examples":[],"pfam_id":"PF14298","short_name":"XusB","status":"NO_SIBLING_CANDIDATE","unresolved":[]}}