[NMR paper] Solid-State NMR Study of a 41 kDa Membrane Protein Complex DsbA/DsbB.

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Solid-State NMR Study of a 41 kDa Membrane Protein Complex DsbA/DsbB.

Related Articles Solid-State NMR Study of a 41 kDa Membrane Protein Complex DsbA/DsbB.

J Phys Chem B. 2013 Mar 25;

Authors: Sperling LJ, Tang M, Berthold DA, Nesbitt AE, Gennis RB, Rienstra CM

Abstract
The disulfide bond generation system in E. coli is led by a periplasmic protein DsbA and an integral membrane protein DsbB. Here we present a solid-state NMR (SSNMR) study of a 41 kDa membrane protein complex DsbA/DsbB precipitated in the presence of native lipids to investigate conformational changes and dynamics that occur upon transient complex formation within the electron transfer pathway. Chemical shift changes in the periplasmic enzyme DsbA of the three states (wild type, C33S mutant and complex with DsbB) reveal structural and/or dynamic information. We report a 4.9 ppm 15N chemical shift change observed for Pro31 in the active site between the wild type and C33S mutant of DsbA. Additionally, the Pro31 residue remains elusive in the DsbA/DsbB complex, indicating that the dynamics change drastically in the active site between the three states of DsbA. Partial 13C and 15N de novo chemical shift assignments throughout DsbA in the DsbA/DsbB complex using three-dimensional SSNMR spectra were compared with the shifts from DsbA alone to map the site-specific chemical shift perturbations. These results demonstrate that there are further structural and dynamic changes of DsbA in the native membrane observed by SSNMR, which is beyond the differences between the crystal structures of DsbA and the DsbA/DsbB complex.


PMID: 23527473 [PubMed - as supplied by publisher]



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