Molecular cloning and characterization of a novel human putative transmembrane protein homologous to mouse sideroflexin associated with sideroblastic anemia

DNA Seq. 2003 Oct;14(5):369-73. doi: 10.1080/10425170310001605491.


Sideroflexin1 (Sfxn1), the prototype of a novel family of evolutionarily conserved proteins present in eukaryotes, has been found mutated in mice with siderocytic anemia. It is speculated that this protein facilitates the transport of a component required for iron utilization into mitochondrial. During the large-scale sequencing analysis of a human fetal brain cDNA library, we isolated a cDNA encoding a novel sideroflexin protein (SFXN4), which showed 59% identity and 71% similarity to mouse sideroflexin4. According to the search of the human genome database, SFXN4 gene is mapped to chromosome 10q25-26 and spans more than 24.7kb of the genomic DNA. It is 1428 base pair in length and the putative protein contains 305 amino acids with a conserved predicted five-transmembrane-domains structure. RT-PCR result shows that the SFXN4 gene is expressed in many tissues.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Anemia, Sideroblastic / genetics*
  • Animals
  • Base Sequence
  • Cation Transport Proteins / chemistry
  • Cation Transport Proteins / genetics*
  • Chromosome Mapping
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • DNA, Complementary / isolation & purification
  • Gene Library
  • Humans
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics*
  • Mice
  • Molecular Sequence Data
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid


  • Cation Transport Proteins
  • DNA, Complementary
  • Membrane Proteins
  • SFXN4 protein, human
  • Sfxn1 protein, mouse

Associated data

  • GENBANK/AY269785