title: Arabidopsis AtIscA-I is affected by deficiency of Fe-S cluster biosynthetic scaffold AtCnfU-V.
abstract: IscA has been proposed to be a scaffold protein of the iron-sulfur cluster biosynthetic machinery. We have identified the IscA homolog to be localized to plastids, termed AtIscA-I, in Arabidopsis thaliana. The AtIscA-I protein was apparently constitutively expressed in all tissues analyzed in Arabidopsis. The AtIscA-I protein exists in the stroma as a soluble protein which tends to form a homo-dimer and can host a [2Fe-2S]-like cluster. Complete loss of the protein from plastids did not cause any significant defect either in normal plant growth or in biogenesis of major iron-sulfur proteins, indicating this protein is not essential or redundant for these functions. In contrast, loss of one of the three plastid-localized CnfU scaffold proteins, AtCnfU-V, caused significant reduction in the level of AtIscA-I. These data suggest that efficient biogenesis of AtIscA-I scaffold requires function of another essential scaffold protein CnfU.
authors.affiliation: Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita 565-0871, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Yabe
authors.forename: Masato
authors.initials: M
authors.lastname: Nakai
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D034521:Nuclear Matrix-Associated Proteins / Q000378:metabolism*; D001678:Organelle Biogenesis; D018514:Plant Structures / Q000235:genetics / Q000378:metabolism; D018087:Plastids / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C508776:CnfU-V protein, Arabidopsis; D007506:Iron-Sulfur Proteins; C508775:IscA-I protein, Arabidopsis; D034521:Nuclear Matrix-Associated Proteins; D011994:Recombinant Proteins