1t0f
From Proteopedia
Crystal Structure of the TnsA/TnsC(504-555) complex
Structural highlights
Function[TNSA_ECOLX] Required for Tn7 transposition. Forms the transposase, together with TnsB. TnsA executes the 5'-DNA strand breakage reaction. TnsABC and TnsD promote high-frequency insertion of Tn7 into a specific target site known as ATT-Tn7 whereas TnsABC and TnsD promote low-frequency insertion into many different sites.[1] [2] [TNSC_ECOLX] TnsC binds non-specifically to DNA in the presence of ATP. It is required for Tn7 transposition. TnsABC + TnsD promote high-frequency insertion of Tn7 into a specific target site known as att-Tn7 whereas TnsABC + TnsE promote low-frequency insertion into many different sites. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedTn7 transposition requires the assembly of a nucleoprotein complex containing four self-encoded proteins, transposon ends, and target DNA. Within this complex, TnsC, the molecular switch that regulates transposition, and TnsA, one part of the transposase, interact directly. Here, we demonstrate that residues 504-555 of TnsC are responsible for TnsA/TnsC interaction. The crystal structure of the TnsA/TnsC(504-555) complex, resolved to 1.85 A, illustrates the burial of a large hydrophobic patch on the surface of TnsA. One consequence of sequestering this patch is a marked increase in the thermal stability of TnsA as shown by differential scanning calorimetry. A model based on the complex structure suggested that TnsA and a slightly longer version of the cocrystallized TnsC fragment (residues 495-555) might cooperate to bind DNA, a prediction confirmed using gel mobility shift assays. Donor DNA binding by the TnsA/TnsC(495-555) complex is correlated with the activation of the TnsAB transposase, as measured by double-stranded DNA cleavage assays, demonstrating the importance of the TnsA/TnsC interaction in affecting Tn7 transposition. The carboxy-terminal portion of TnsC activates the Tn7 transposase through a specific interaction with TnsA.,Ronning DR, Li Y, Perez ZN, Ross PD, Hickman AB, Craig NL, Dyda F EMBO J. 2004 Aug 4;23(15):2972-81. Epub 2004 Jul 15. PMID:15257292[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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