Transient B12-Dependent Methyltransferase Complexes Revealed by Small-Angle X-ray Scattering
Name
Drennan_Transient B.pdf
Size
4.96 MB
Format
Adobe PDF
Checksum (MD5)
1abeabfcb0e06e99c72261d54d48c613
Author(s)
Ando, Nozomi
Kung, Yan
Can, Mehmet
Bender, Güneş
Ragsdale, Stephen W.
Drennan, Catherine L
Date Issued
October 2012
Journal
Journal of the American Chemical Society
Publisher
American Chemical Society
Citation
Ando, Nozomi, Yan Kung, Mehmet Can, Gunes Bender, Stephen W. Ragsdale, and Catherine L. Drennan. “Transient B12-Dependent Methyltransferase Complexes Revealed by Small-Angle X-ray Scattering.” Journal of the American Chemical Society 134, no. 43 (October 31, 2012): 17945-17954. © 2012 American Chemical Society.
Version
Final published version
Abstract
In the Wood−Ljungdahl carbon fixation pathway, protein−protein interactions between methyltransferase (MeTr) and corrinoid iron−sulfur protein (CFeSP) are required for the transfer of a methyl group. While crystal structures have been determined for MeTr and CFeSP both free and in complex, solution structures have not been established. Here, we examine the transient interactions between MeTr and CFeSP in solution using anaerobic small-angle Xray scattering (SAXS) and present a global analysis approach for the deconvolution of heterogeneous mixtures formed by weakly interacting proteins. We further support this SAXS analysis with complementary results obtained by anaerobic isothermal titration calorimetry. Our results indicate that solution conditions affect the cooperativity with which CFeSP binds to MeTr, resulting in two distinct CFeSP/MeTr complexes with differing oligomeric compositions, both of which are active. One assembly resembles the CFeSP/MeTr complex observed crystallographically with 2:1 protein stoichiometry, while the other best fits a 1:1 CFeSP/MeTr arrangement. These results demonstrate the value of SAXS in uncovering the rich solution behavior of transient protein interactions visualized by crystallography.
MIT Department
Massachusetts Institute of Technology. Department of Biology
Massachusetts Institute of Technology. Department of Chemistry
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1021/ja3055782
