| Autor: |
Geng J; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China., Luo S; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.; University of Chinese Academy of Sciences, Beijing 100049, China., Shieh HR; Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan., Wang HY; Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan., Hu S; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.; University of Chinese Academy of Sciences, Beijing 100049, China., Chen YM; Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.; Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan. |
| Abstrakt: |
CodY is a dominant regulator in low G + C, Gram-positive Firmicutes that governs the regulation of various metabolic pathways and cellular processes. By using various bioinformatics analyses and DNA affinity precipitation assay (DAPA), this study confirmed the presence of CodY orthologues and corresponding regulons in Gram-negative Synergistetes. A novel palindromic sequence consisting of AT-rich arms separated by a spacer region of variable length and sequence was identified in the promoters of the putative codY -containing operons in Synergistetes. The consensus sequence from genera Synergistes and Cloacibacillus (5'-AATTTTCTTAAAATTTCSCTTGATATTTACAATTTT) contained three AT-rich regions, resulting in two palindromic sequences; one of which is identical to Firmicutes CodY box (5'-AATTTTCWGAAAATT). The function of the consensus sequence was tested by using a recombinant CodY protein (His-CodY DSM ) of Cloacibacillus evryensis DSM19522 in DAPA. Mutations in the central AT-rich sequence reduced significantly the binding of His-CodY DSM , whereas mutations in the 5' or 3' end AT-rich sequence slightly reduced the binding, indicating that CodY DSM could recognize both palindromic sequences. The proposed binding sequences were found in the promoters of multiple genes involved in amino acids biosynthesis, metabolism, regulation, and stress responses in Synergistetes. Thus, a CodY-like protein from Synergistetes may function similarly to Firmicutes CodY. |
