title: Molybdenum induces the expression of a protein containing a new heterometallic Mo-Fe cluster in Desulfovibrio alaskensis.
abstract: The characterization of a novel Mo-Fe protein (MorP) associated with a system that responds to Mo in Desulfovibrio alaskensis is reported. Biochemical characterization shows that MorP is a periplasmic homomultimer of high molecular weight (260 +/- 13 kDa) consisting of 16-18 monomers of 15321.1 +/- 0.5 Da. The UV/visible absorption spectrum of the as-isolated protein shows absorption peaks around 280, 320, and 570 nm with extinction coefficients of 18700, 12800, and 5000 M(-1) cm(-1), respectively. Metal content, EXAFS data and DFT calculations support the presence of a Mo-2S-[2Fe-2S]-2S-Mo cluster never reported before. Analysis of the available genomes from Desulfovibrio species shows that the MorP encoding gene is located downstream of a sensor and a regulator gene. This type of gene arrangement, called two component system, is used by the cell to regulate diverse physiological processes in response to changes in environmental conditions. Increase of both gene expression and protein production was observed when cells were cultured in the presence of 45 microM molybdenum. Involvement of this system in Mo tolerance of sulfate reducing bacteria is proposed.
authors.affiliation: REQUIMTE/CQFB, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Maria G
authors.initials: MG
authors.lastname: Rivas
authors.forename: Marta S P
authors.initials: MS
authors.lastname: Carepo
authors.forename: Cristiano S
authors.initials: CS
authors.lastname: Mota
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Korbas
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Durand
authors.forename: Ana T
authors.initials: AT
authors.lastname: Lopes
authors.forename: Carlos D
authors.initials: CD
authors.lastname: Brondino
authors.forename: Alice S
authors.initials: AS
authors.lastname: Pereira
authors.forename: Graham N
authors.initials: GN
authors.lastname: George
authors.forename: Alain
authors.initials: A
authors.lastname: Dolla
authors.forename: José J G
authors.initials: JJ
authors.lastname: Moura
authors.forename: Isabel
authors.initials: I
authors.lastname: Moura
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D003901:Desulfovibrio / Q000737:chemistry* / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D007501:Iron / Q000378:metabolism*; D008667:Metalloproteins / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D008982:Molybdenum / Q000737:chemistry* / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D008667:Metalloproteins; D008982:Molybdenum; D007501:Iron