A novel DNA modification by sulfur: DndA is a NifS-like cysteine desulfurase capable of assembling DndC as an iron-sulfur cluster protein in Streptomyces lividans.
A novel DNA modification system by sulfur (S) in Streptomyces lividans 66 was reported to be encoded by a cluster of five genes designated dndA-E [Zhou, X., He, X., Liang, J., Li, A., Xu, T., Kieser, T., Helmann, J. D., and Deng, Z. (2005) Mol. Microbiol. 57, 1428-1438]. The dndA gene was cloned and the protein product expressed in Escherichia coli, purified to homogeneity, and characterized as a homodimeric protein of ca. 91 kDa. Purified DndA has a yellow color and UV-visible spectra characteristic of a pyridoxal phosphate-containing enzyme and was proven to be a cysteine desulfurase able to catalyze removal of elemental S atoms from l-cysteine to produce l-alanine with substrate specificity similar to that of E. coli IscS. DndC was also purified to homogeneity and found to contain a 4Fe-4S cluster by spectral analysis and have obvious ATP pyrophosphatase activity. DndA could catalyze iron-sulfur cluster assembly by activation of apo-Fe DndC protein prepared by removal of its iron-sulfur cluster using alpha,alpha'-dipyridyl. A mutated DndA, with serine substituted for cysteine at position 327, which was confirmed to have lost its corresponding cysteine desulfurase activity, also lost its ability to reactivate the apo-Fe DndC. The likely involvement of an interaction between DndA and DndC in the biochemical pathway for the unusual site-specific DNA modification in S. lividans 66 is discussed.
You
Delin
D
Laboratory of Microbial Metabolism and College of Life Science and Biotechnology, Shanghai Jiaotong University, Shanghai 200030, China.
Wang
Lianrong
L
Yao
Fen
F
Zhou
Xiufen
X
Deng
Zixin
Z
D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D013437:Carbon-Sulfur Lyases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D005810:Multigene Family; D009713:Nucleotidyltransferases / Q000737:chemistry; D010088:Oxidoreductases / Q000737:chemistry; D011499:Protein Processing, Post-Translational / Q000235:genetics; D021122:Protein Subunits / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D048170:Streptomyces lividans / Q000201:enzymology* / Q000235:genetics; D013455:Sulfur / Q000737:chemistry
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D007506:Iron-Sulfur Proteins; D021122:Protein Subunits; C080001:nifS protein, Bacteria; D013455:Sulfur; D010088:Oxidoreductases; C052449:3'-phosphoadenylyl-5'-phosphosulfate reductase; D009713:Nucleotidyltransferases; C062599:sulfate adenylyltransferase (ADP); D013437:Carbon-Sulfur Lyases; C080546:cysteine desulfurase