|
type |
Journal Article |
authors |
You D, Wang L, Yao F, Zhou X, Deng Z. |
title |
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 |
journal |
Biochemistry |
Activity |
2.8.1.7 |
Family |
2.8.1.7.a |
sel |
selected |
ui |
17469805 |
year |
(2007) |
volume |
46 |
number |
20 |
pages |
6126-33 |
| |
abstract |
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. |
last changed |
2007/12/18 11:45 |
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