title: Characterization of the cDNA and amino acid sequences of Xenopus Metaxin 3, and relationship to Xenopus Metaxins 1 and 2.
abstract: The cDNA and protein structures of Xenopus metaxin 3, along with those of Xenopus metaxins 1 and 2, have been characterized. A protein of 309 amino acid residues is encoded by X. laevis metaxin 3 (XMTX3) cDNA. In comparison, the cDNA of X. laevis metaxin 1 (XMTX1) specifies a protein of 320 residues, while the metaxin 2 cDNAs of X. laevis (XMTX2) and X. tropicalis (SMTX2) both specify proteins of 274 amino acids. Aligning the amino acid sequences of XMTX3 and XMTX1 showed 39% identities; 22% identities were found for XMTX3 and XMTX2. However, 55% amino acid identities were revealed in aligning the XMTX3 and zebrafish metaxin 3 sequences. The construction of a phylogenetic tree gave further evidence for the existence of three distinct groups of metaxin genes and their common ancestry. Two conserved protein domains are present in each of the Xenopus metaxins: a glutathione S-transferase (GST) domain and a thioredoxin-like domain. The protein secondary structure predicted for the Xenopus metaxins is dominated by regions of alpha helix which alternate with regions that are neither alpha helix nor beta strand.
authors.affiliation: Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church Street SE, Minneapolis, MN, 55455, USA. adolp001@umn.edu
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Adolph
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D017433:Protein Structure, Secondary / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014981:Xenopus / Q000235:genetics*; D029867:Xenopus Proteins / Q000235:genetics; D029961:Zebrafish Proteins / Q000235:genetics
chemical_list: D018076:DNA, Complementary; C507398:MTX1 protein, Xenopus; C507399:MTX2 protein, Xenopus; C507400:MTX3 protein, Xenopus; C488266:MTX3 protein, zebrafish; D008565:Membrane Proteins; D029867:Xenopus Proteins; D029961:Zebrafish Proteins