Q9VF20 is the 866-residue PA product of FBgn0038376 (AAF55241/NP_650503), the single currently annotated protein. FlyBase. The exact source sequence has the ABCB6 N-terminal domain (IPR032410), transmembrane ABC domain and ABC nucleotide-binding cassette; it is not identified solely by its automated full name.
PMID:19001374(https://pubmed.ncbi.nlm.nih.gov/19001374/) directly studies DmHMT-1 expressed in Schizosaccharomyces pombe. The abstract states that it “suppresses the Cd2+ hypersensitivity of S. pombe hmt-1 mutants and localizes to the vacuolar membrane but does not transport Cd.PC complexes.” This supports the existing IGI detoxification and IDA localization annotations with the explicit heterologous-system qualification. The cache remains abstract-only after a forced retrieval attempt; no full-text assay details are invented. In particular, cadmium tolerance is not equated with transport of free Cd2+ or a phytochelatin complex.
PMID:35950458(https://pmc.ncbi.nlm.nih.gov/articles/PMC9385563/) is cached with full text. It resolves human ABCB6 with coproporphyrin III and hemin, including hemin coordinated with glutathione. This gives substrate-level biological grounding for the curated ABCB6 ancestral assignment, supported by target family architecture. Heme binding/transport is retained as a non-core conserved capability; the best demonstrated target role is cadmium tolerance. Broad ProtNLM ABC transporter activity is therefore LSP relative to the supported family-specific activity, rather than uncertain simply because the exact fly physiological solute is unknown.
The extensive automated location list is not treated as ten independent observations. Yeast vacuolar targeting does not establish extracellular, mitochondrial, Golgi, ER, plasma-membrane or individual endosomal locations in the fly. These specific rows remain UNDECIDED pending target localization or a conserved targeting mechanism. Lysosomal membrane is plausible as a homologous compartment, but the experiment itself uses a yeast vacuole; the existing vacuolar annotation is the resolved level.
The Falcon report completed and was inspected. It correctly separates yeast-complementation evidence from native fly localization and emphasizes unresolved metal speciation. Its heme discussion lacks the substrate-resolved 2022 ABCB6 study used here, so the review retains a qualified conserved heme-handling capability rather than requiring a new fly assay for every family property. The provider's broad metal-selectivity discussion is not imported: in the cached primary abstract, the Hg/As comparison is explicitly about SpHMT-1-deficient cells. The provider's 2024 cadmium-structure lead is useful, but not counted as a replicated DmHMT-1 transport experiment.