title: Mycobacterium smegmatis Lsr2 physically and functionally interacts with a new flavoprotein involved in bacterial resistance to oxidative stress.
abstract: Lsr2, a bacterial histone-like protein, has been shown to be clearly involved in modulating chromatin organization, compaction and global gene expression. However, the regulatory mechanism of its functions remains largely unclear. In this study, using bacterial two-hybrid technique and pull-down assays, the Mycobacterium smegmatis Lsr2 was detected to associate with a hypothetical flavoprotein, Ms4334. A further co-immunoprecipitation assay confirmed the physical interaction between these two proteins in vivo in mycobacteria. Importantly, the Ms4334 protein was also capable of enhancing the inhibitory effect of Lsr2 in vitro on the function of DNA topoisomerase I (MsTopA). Therefore, Lsr2 could physically and functionally interact with Ms4334. Further, the Ms4334 gene was confirmed to encode a new FAD-binding flavoprotein that displayed two characteristic absorption peaks at about 370 and 450 nm in a UV-visible spectra scanning assay. Interestingly, when comparing the growths of wild-type M. smegmatis with the Ms4334-knockout strain in response to H(2)O(2), Ms4334 was found to contribute to mycobacterial resistance to oxidative stress. The findings provided important clues for a further understanding of the regulation mechanism of Lsr2 in mycobacteria.
authors.affiliation: National Key Laboratory of Agricultural Microbiology, Center for Proteomics Research, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Du
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: He
authors.forename: Feng
authors.initials: F
authors.lastname: Huang
authors.forename: Zheng-Guo
authors.initials: ZG
authors.lastname: He
mesh_terms: D000942:Antigens, Bacterial / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D005420:Flavoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020102:Mycobacterium smegmatis / Q000737:chemistry / Q000378:metabolism*; D018384:Oxidative Stress; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D005420:Flavoproteins; C507916:Lsr2 protein, Mycobacterium smegmatis; D011994:Recombinant Proteins