Structural basis for the inhibition of the Bacillus subtilis c-di-AMP cyclase CdaA by the phosphoglucomutase GlmM
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Cyclic-di-adenosine monophosphate (c-di-AMP) is an important nucleotide signaling molecule that plays a key role in osmotic regulation in bacteria. c-di-AMP is produced from two molecules of ATP by proteins containing a diadenylate cyclase (DAC) domain. In Bacillus subtilis, the main c-di-AMP cyclase, CdaA, is a membrane-linked cyclase with an N-terminal transmembrane domain followed by the cytoplasmic DAC domain. As both high and low levels of c-di-AMP have a negative impact on bacterial growth, the cellular levels of this signaling nucleotide are tightly regulated. Here we investigated how the activity of the B. subtilis CdaA is regulated by the phosphoglucomutase GlmM, which has been shown to interact with the c-di-AMP cyclase. Using the soluble B. subtilis CdaACD catalytic domain and purified full-length GlmM or the GlmMF369 variant lacking the C-terminal flexible domain 4, we show that the cyclase and phosphoglucomutase form a stable complex in vitro and that GlmM is a potent cyclase inhibitor. We determined the crystal structure of the individual B. subtilis CdaACD and GlmM homodimers and of the CdaACD:GlmMF369 complex. In the complex structure, a CdaACD dimer is bound to a GlmMF369 dimer in such a manner that GlmM blocks the oligomerization of CdaACD and formation of active head-to-head cyclase oligomers, thus suggesting a mechanism by which GlmM acts as a cyclase inhibitor. As the amino acids at the CdaACD:GlmM interphase are conserved, we propose that the observed mechanism of inhibition of CdaA by GlmM may also be conserved among Firmicutes.
Date Issued
2021-10-20
Date Acceptance
2021-10-15
Citation
Journal of Biological Chemistry, 2021, 297 (5), pp.1-15
ISSN
0021-9258
Publisher
American Society for Biochemistry and Molecular Biology
Start Page
1
End Page
15
Journal / Book Title
Journal of Biological Chemistry
Volume
297
Issue
5
Copyright Statement
© 2021 THE AUTHORS. Published by Elsevier Inc on behalf of American Society for Biochemistry and Molecular Biology. This is an open access article under the CC
BY license (http://creativecommons.org/licenses/by/4.0/)
BY license (http://creativecommons.org/licenses/by/4.0/)
License URL
Sponsor
Medical Research Council (MRC)
Wellcome Trust
Wellcome Trust
Identifier
https://www.sciencedirect.com/science/article/pii/S0021925821011236?via%3Dihub
Grant Number
G0701212
202926/Z/16/Z
210671/Z/18/Z
Subjects
Bacillus
crystallography
cyclic dinucleotide
protein structure
signaling
03 Chemical Sciences
06 Biological Sciences
11 Medical and Health Sciences
Biochemistry & Molecular Biology
Publication Status
Published
Date Publish Online
2021-10-20