Molybdenum induces the expression of a new Mo–Fe heterometallic protein in Desulfovibrio alaskensis

M.S.P. CAREPO; M.G. RIVAS; C.S. MOTA; M. KORBAS; M.C. DURAND; A.T. LOPES; S.C.M. MATOS; C.D. BRONDINO; A. PEREIRA; G.N. GEORGE; A. DOLLA; J.J.G. MOURA; I. MOURA

Nagoya (Japan)

Conferencia; 14th International Conference on Biological Inorganic Chemistry; 2009

Sulfate-reducing bacteria (SRB) contain several Mo–proteins that have been characterized; however, there are no reports addressing Mo homeostasis. In this work we report the characterization of a novel Mo– Fe protein (MorP) associated with a system that responds to Mo in Desulfovibrio alaskensis. MorP is a periplasmic homomultimer of high molecular weight (260 kDa) consisting of 16–18 monomers of 15.3 kDa. Metal content,EXAFSdata andDFTcalculations support the presence of a Mo–2S–[2Fe–2S]–2S–Mo cluster never reported before. MorP encoding gene is located downstream of a sensor (morS) and a regulator gene (morR), encoding a two-component system. Increase of both gene expression and protein production was observed when cells were cultured in the presence of 45 lM. In the same growth conditions the morR gene expression was also up-regulated. MorR was heterolo- gously expressed in E. coli and is currently being characterized.