title: An intrinsically disordered domain has a dual function coupled to compartment-dependent redox control.
abstract: The functional role of unstructured protein domains is an emerging field in the frame of intrinsically disordered proteins. The involvement of intrinsically disordered domains (IDDs) in protein targeting and biogenesis processes in mitochondria is so far not known. Here, we have characterized the structural/dynamic and functional properties of an IDD of the sulfhydryl oxidase ALR (augmenter of liver regeneration) located in the intermembrane space of mitochondria. At variance to the unfolded-to-folded structural transition of several intrinsically disordered proteins, neither substrate recognition events nor redox switch of its shuttle cysteine pair is linked to any such structural change. However, this unstructured domain performs a dual function in two cellular compartments: it acts (i) as a mitochondrial targeting signal in the cytosol and (ii) as a crucial recognition site in the disulfide relay system of intermembrane space. This domain provides an exciting new paradigm for IDDs ensuring two distinct functions that are linked to intracellular organelle targeting.
authors.affiliation: Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy. banci@cerm.unifi.it
authors.forename: Lucia
authors.initials: L
authors.lastname: Banci
authors.forename: Ivano
authors.initials: I
authors.lastname: Bertini
authors.forename: Chiara
authors.initials: C
authors.lastname: Cefaro
authors.forename: Simone
authors.initials: S
authors.lastname: Ciofi-Baffoni
authors.forename: Karolina
authors.initials: K
authors.lastname: Gajda
authors.forename: Isabella C
authors.initials: IC
authors.lastname: Felli
authors.forename: Angelo
authors.initials: A
authors.lastname: Gallo
authors.forename: Anna
authors.initials: A
authors.lastname: Pavelkova
authors.forename: Emmanouela
authors.initials: E
authors.lastname: Kallergi
authors.forename: Maria
authors.initials: M
authors.lastname: Andreadaki
authors.forename: Nitsa
authors.initials: N
authors.lastname: Katrakili
authors.forename: Charalambos
authors.initials: C
authors.lastname: Pozidis
authors.forename: Kostas
authors.initials: K
authors.lastname: Tokatlidis
mesh_terms: D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D050862:Oxidoreductases Acting on Sulfur Group Donors
chemical_list: D024101:Mitochondrial Proteins; D011506:Proteins; C088825:GFER protein, rat; D050862:Oxidoreductases Acting on Sulfur Group Donors