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Assignment-free solution NMR method reveals CesT as an unswapped homodimer.

ABSTRACT: The X-ray structure of the homodimeric chaperone CesT is the only structure among the type three secretion system (TTSS) chaperones that shows a domain swap. This swap has potential importance for the mechanism of effector translocation through a TTSS. Here we present two nuclear magnetic resonance strategies exploiting pre-existing structural models and residual dipolar couplings (RDCs), which reveal the unswapped 35.4-kDa dimer to be present in solution. Particularly efficient is the discrimination of a swapped and unswapped structural state performed simultaneously to automatic backbone assignment using only HN-RDCs and carbonyl backbone chemical shifts. This direct approach may prove to be generally useful to rapidly differentiate two structural models.

SUBMITTER: Rumpel S

PROVIDER: S-EPMC2578808 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature

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Assignment-free solution NMR method reveals CesT as an unswapped homodimer.

Rumpel Sigrun S Lakshmi Raghavendran R Becker Stefan S Zweckstetter Markus M

Protein science : a publication of the Protein Society 20080807 11

The X-ray structure of the homodimeric chaperone CesT is the only structure among the type three secretion system (TTSS) chaperones that shows a domain swap. This swap has potential importance for the mechanism of effector translocation through a TTSS. Here we present two nuclear magnetic resonance strategies exploiting pre-existing structural models and residual dipolar couplings (RDCs), which reveal the unswapped 35.4-kDa dimer to be present in solution. Particularly efficient is the discrimin ...[more]

PMID: 18687869

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