Molybdenum induces the expression of a protein containing a new heterometallic Mo-Fe cluster in Desulfovibrio alaskensis.
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.
Rivas
Maria G
MG
REQUIMTE/CQFB, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
Carepo
Marta S P
MS
Mota
Cristiano S
CS
Korbas
Malgorzata
M
Durand
Marie-Claire
MC
Lopes
Ana T
AT
Brondino
Carlos D
CD
Pereira
Alice S
AS
George
Graham N
GN
Dolla
Alain
A
Moura
José J G
JJ
Moura
Isabel
I
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
D001426:Bacterial Proteins; D008667:Metalloproteins; D008982:Molybdenum; D007501:Iron