2kng
From Proteopedia
Solution structure of C-domain of Lsr2
Structural highlights
FunctionLSR2_MYCTU DNA-bridging protein that has both architectural and regulatory roles. Influences the organization of chromatin and gene expression by binding non-specifically to DNA, with a preference for AT-rich sequences, and bridging distant DNA segments. Represses expression of multiple genes involved in a broad range of cellular processes, including major virulence factors or antibiotic-induced genes, such as iniBAC or efpA. May coordinate global gene regulation and virulence. Also protects mycobacteria against reactive oxygen intermediates during macrophage infection by acting as a physical barrier to DNA degradation.[1] [2] [3] [4] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBacterial nucleoid-associated proteins play important roles in chromosome organization and global gene regulation. We find that Lsr2 of Mycobacterium tuberculosis is a unique nucleoid-associated protein that binds AT-rich regions of the genome, including genomic islands acquired by horizontal gene transfer and regions encoding major virulence factors, such as the ESX secretion systems, the lipid virulence factors PDIM and PGL, and the PE/PPE families of antigenic proteins. Comparison of genome-wide binding data with expression data indicates that Lsr2 binding results in transcriptional repression. Domain-swapping experiments demonstrate that Lsr2 has an N-terminal dimerization domain and a C-terminal DNA-binding domain. Nuclear magnetic resonance analysis of the DNA-binding domain of Lsr2 and its interaction with DNA reveals a unique structure and a unique mechanism that enables Lsr2 to discriminately target AT-rich sequences through interactions with the minor groove of DNA. Taken together, we provide evidence that mycobacteria have employed a structurally distinct molecule with an apparently different DNA recognition mechanism to achieve a function similar to the Enterobacteriaceae H-NS, likely coordinating global gene regulation and virulence in this group of medically important bacteria. Lsr2 is a nucleoid-associated protein that targets AT-rich sequences and virulence genes in Mycobacterium tuberculosis.,Gordon BR, Li Y, Wang L, Sintsova A, van Bakel H, Tian S, Navarre WW, Xia B, Liu J Proc Natl Acad Sci U S A. 2010 Jan 20. PMID:20133735[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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