A Novel AT-Rich DNA Recognition Mechanism for Bacterial Xenogeneic Silencer MvaT

• DOI: 10.1371/journal.ppat.1004967
• Publication Date: 2015-06-11T14:09:39Z
• Authors: Pengfei Ding; Kirsty A. McFarland; Shujuan Jin; Grace Tong; Bo Duan; Ally Yang; Timothy R. Hughes; Jun Liu; Simon L. Dove; William Wiley Nav...; Bin Xia
• Keywords: Silencer

Bacterial xenogeneic silencing proteins selectively bind to and silence expression from many AT rich regions of the chromosome. They serve as master regulators horizontally acquired DNA, including a large number virulence genes. To date, three distinct families silencers have been identified: H-NS Proteobacteria, Lsr2 Actinomycetes, MvaT Pseudomonas sp. Although family are structurally different, they all recognize AT-rich DNA minor groove through common AT-hook-like motif, which is absent in family. Thus, binding mechanism has not determined. Here, we report characteristics sequences targeted by with protein microarrays, indicates that prefers flexible multiple TpA steps. We demonstrate there clear differences sequence preferences between other two silencer families. also determined structure DNA-binding domain complex high affinity dodecamer using solution NMR. This first experimental reveals recognizes both base readout an "AT-pincer" motif inserted into shape lysine side chains interacting sugar-phosphate backbone. Mutations key residues for confirm their importance vitro vivo assays. novel mode enables better tolerate GC-base pair interruptions site less prefer A tract when compared Lsr2. Comparison bacterial provides picture nature evolved unique solutions different genera distinguish foreign self DNA.