STEAP3

STEAP family member 3

Rendering based on PDB 2VNS.
Identifiers
Symbols STEAP3; STMP3; TSAP6; dudlin-2
External IDs OMIM609671 MGI1915678 HomoloGene10084 GeneCards: STEAP3 Gene
EC number 1.16.1.-
RNA expression pattern
More reference expression data
Orthologs
Species Human Mouse
Entrez 55240 68428
Ensembl ENSG00000115107 ENSMUSG00000026389
UniProt Q658P3 Q8CI59
RefSeq (mRNA) NM_001008410.1 NM_133186
RefSeq (protein) NP_001008410.1 NP_573449
Location (UCSC) Chr 2:
119.98 – 120.02 Mb
Chr 1:
122.09 – 122.17 Mb
PubMed search [1] [2]

Metalloreductase STEAP3 is an enzyme that in humans is encoded by the STEAP3 gene.[1][2]

STEAP3 is a metalloreductase, capable of coverting iron from an insoluble ferric (Fe3+) to a soluble ferrous (Fe2+) form.[3]

The daily production of 200 billion erythrocytes requires 20 mg of iron, accounting for nearly 80% of the iron demand in humans. Thus, erythroid precursor cells possess an efficient mechanism for iron uptake in which iron loaded transferrin (Tf) binds to the transferrin receptor (TfR) at the cell surface. The Tf:TfR complex then enters the endosome via receptor-mediated endocytosis. Upon endosomal acidification, iron is released from Tf, reduced to Fe2+ by Steap3, and transported across the endosomal membrane by divalent metal ion transporter 1. Steap3 is composed of an N-terminal cytosolic oxidoreductase domain and a C-terminal heme-containing transmembrane domain. The NADPH/flavin binding domain of Steap3 differs significantly from those in other eukaryotic reductases. Steap3 shows remarkable, although limited homology to FNO, an archaeal oxidoreductase. We have determined the crystal structure of the human-Steap3 oxidoreductase domain in the absence and presence of NADPH (PDB-ID 2vns and 2vq3). The structure of the oxidoreductase domain reveals an unexpected dimer interface and substrate binding sites that are well positioned to direct electron transfer from the cytosol to a transmembrane heme moiety. [4]

Interactions

STEAP3 has been shown to interact with BNIP3L[1] and PKMYT1.[1]

References

Further reading