Mobilization of sulfane sulfur from cysteine desulfurases to the Azotobacter vinelandii sulfurtransferase RhdA

Abstract

Mobilization of the L-cysteine sulfur for the persulfuration of the rhodanese of Azotobacter vinelandii, RhdA, can be mediated by the A. vinelandii cysteine desulfurases, IscS and NifS. The amount of cysteine was higher in mutant strains lacking rhdA (MV474) than in wild type. The diazotrophic growth of MV474 was impaired. Taking into account the functional results about rhodanese-like proteins and RhdA itself, it is suggested that RhdA-dependent modulation of L-cysteine levels must deal with a redox-related process.

A dual role of the transcriptional regulator TstR provides insights into cyanide detoxification in Lactobacillus brevis

“…Protein–protein interaction phenomena involving sulphurtransferase activity have been recently described in the process of sulphur compound homeostasis (i.e. IscS and FdhD, Thomé et al ., ; NifS or IscS and RhdA, Cartini et al ., ). However, scarce information is available regarding protein–protein interaction events involving transcriptional regulators and enzymes (Wilke et al ., ; Garcia et al ., ).…”

Expression of soluble native protein in Escherichia coli using a cold-shock SUMO tag-fused expression vector

“…The cysteine residue is involved in the formation of a protein-bound cysteine persulfide intermediate, which serves as a sulfur donor and is subsequently incorporated to the biosynthesis of sulfur-containing biomolecules namely, biotin, thiamine, molybdopterin, and Fe-S clusters in proteins [ 20 , 21 ]. In addition, cysteine desulfurases act in the maintance of the balance of iron in vivo , and participate in the modification of tRNA and the phosphorothioation of DNA [ 22 , 23 ]. However, the specific catalytic mechanism of NFS1 was poorly understood, due to its insoluble status using the present production methods [ 4 ].…”

Involvement of the Azotobacter vinelandii Rhodanese-Like Protein RhdA in the Glutathione Regeneration Pathway

“…Previous works [13], [28] were focussed on the RhdA property to stabilize a persulfide sulfur on the catalytic cysteine residue (Cys 230 ) highlighting a role of RhdA in sulfane sulfur mobilization. It can be supposed that the RhdA-Cys 230 thiol functionally acts according to its state: persulfurated or not.…”

“…His-tagged RhdA and RhdA-Cys 230 Ala were expressed in E. coli strains (BL21[pRep4]) harbouring pQER1 [27] and pQER1MP [13] respectively, and purified by Ni-NTA affinity chromatography [13]. Sulfane sulfur-deprived RhdA was prepared by cyanide treatment as previously described [28] and used for all experiments described in this work.…”