Bahnikana Nanda, Jayantika Bhowmick, Raghavan Varadarajan, Siddhartha P. Sarma
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引用次数: 0
Abstract
The CcdAB system expressed in the E.coli cells is a prototypical example of the bacterial toxin-antitoxin (TA) systems that ensure the survival of the bacterial population under adverse environmental conditions. The solution and crystal structures of CcdA, CcdB and of CcdB in complex with the toxin-binding C-terminal domain of CcdA have been reported. Our interest lies in the dynamics of CcdB-CcdA complex formation. Solution NMR studies have shown that CcdB_G100T, in presence of saturating concentrations of CcdA-c, a truncated C-terminal fragment of CcdA exists in equilibrium between two major populations. Sequence specific backbone resonance assignments of both equilibrium forms of the ~ 27 kDa complex, have been obtained from a suite of triple resonance NMR experiments acquired on 2H, 13C, 15N enriched samples of CcdB_G100T. Analysis of 1H, 13Cα, 13Cβ secondary chemical shifts, shows that both equilibrium forms of CcdB_G100T have five beta-strands and one alpha-helix as the major secondary structural elements in the tertiary structure. The results of these studies are presented below.
期刊介绍:
Biomolecular NMR Assignments provides a forum for publishing sequence-specific resonance assignments for proteins and nucleic acids as Assignment Notes. Chemical shifts for NMR-active nuclei in macromolecules contain detailed information on molecular conformation and properties.
Publication of resonance assignments in Biomolecular NMR Assignments ensures that these data are deposited into a public database at BioMagResBank (BMRB; http://www.bmrb.wisc.edu/), where they are available to other researchers. Coverage includes proteins and nucleic acids; Assignment Notes are processed for rapid online publication and are published in biannual online editions in June and December.