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

作者：You, Delin; Wang, Lianrong; Yao, Fen; Zhou, Xiufen; Deng, Zixin^*

来源：Biochemistry, 2007, 46(20): 6126-6133.

DOI：10.1021/bi602615k

• FE-S CLUSTER
• SYNECHOCYSTIS-SP PCC-6803
• ESCHERICHIA-COLI
• SELENOCYSTEINE LYASE
• 2FE-2S CLUSTER
• AZOTOBACTER-VINELANDII
• BACILLUS-SUBTILIS
• BIOTIN SYNTHASE
• GENE CLONING
• TRANSFER-RNA

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.

• 出版日期2007-5-22
• 单位上海交通大学