Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published September 2013 | Accepted Version + Supplemental Material + Published
Journal Article Open

The mobility of two kinase domains in the Escherichia coli chemoreceptor array varies with signalling state

Abstract

Motile bacteria sense their physical and chemical environment through highly cooperative, ordered arrays of chemoreceptors. These signalling complexes phosphorylate a response regulator which in turn governs flagellar motor reversals, driving cells towards favourable environments. The structural changes that translate chemoeffector binding into the appropriate kinase output are not known. Here, we apply high-resolution electron cryotomography to visualize mutant chemoreceptor signalling arrays in well-defined kinase activity states. The arrays were well ordered in all signalling states, with no discernible differences in receptor conformation at 2–3 nm resolution. Differences were observed, however, in a keel-like density that we identify here as CheA kinase domains P1 and P2, the phosphorylation site domain and the binding domain for response regulator target proteins. Mutant receptor arrays with high kinase activities all exhibited small keels and high proteolysis susceptibility, indicative of mobile P1 and P2 domains. In contrast, arrays in kinase-off signalling states exhibited a range of keel sizes. These findings confirm that chemoreceptor arrays do not undergo large structural changes during signalling, and suggest instead that kinase activity is modulated at least in part by changes in the mobility of key domains.

Additional Information

© 2013 John Wiley & Sons Ltd. Accepted 24 June, 2013. Article first published online: 30 Jul. 2013. This work was supported in part by NIGMS Grants GM101425 (to G.J.J. and J.C.G.) and GM19559 (to J.S.P.), as well as a gift to Caltech from the Gordon and Betty Moore Foundation. The Protein-DNA Core Facility at the University of Utah receives support from National Cancer Institute Grant CA42014 to the Huntsman Cancer Institute.

Attached Files

Published - mmi12309.pdf

Accepted Version - nihms-502238.pdf

Supplemental Material - mmi12309-sup-0001-si.pdf

Files

mmi12309.pdf
Files (13.6 MB)
Name Size Download all
md5:23e19e99cbf2c9c1687d284c1e5e1d7f
1.0 MB Preview Download
md5:2c0f35c378aefd67596b5cda4236a7a2
10.3 MB Preview Download
md5:0db13f458cdffcfd8004c232fd7618c1
2.3 MB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 24, 2023