Journal article
Comparative Study of Bacterial SPOR Domains Identifies Functionally Important Differences in Glycan Binding Affinity
Journal of bacteriology, Vol.204(9), p.1
08/25/2022
DOI: 10.1128/jb.00252-22
PMCID: PMC9487507
PMID: 36005810
Abstract
Bacterial SPOR domains target proteins to the divisome by binding septal peptidoglycan (PG) at sites where cell wall amidases have removed stem peptides. These PG structures are referred to as denuded glycans. Although all characterized SPOR domains bind denuded glycans, whether there are differences in affinity is not known. Here, we use isothermal titration calorimetry (ITC) to determine the relative PG glycan binding affinity (Kd) of four Escherichia coli SPOR domains and one Cytophaga hutchinsonii SPOR domain. We found that the Kd values ranged from approximately 1 μM for E. coli DamXSPOR and C. hutchinsonii CHU2221SPOR to about 10 μM for E. coli FtsNSPOR. To investigate whether these differences in PG binding affinity are important for SPOR domain protein function, we constructed and characterized a set of DamX and FtsN “swap” proteins. As expected, all SPOR domain swap proteins localized to the division site, and, in the case of FtsN, all of the heterologous SPOR domains supported cell division. However, for DamX, only the high-affinity SPOR domain from CHU2221 supported normal function in cell division. In summary, different SPOR domains bind denuded PG glycans with different affinities, which appears to be important for the functions of some SPOR domain proteins (e.g., DamX) but not for the functions of others (e.g., FtsN). IMPORTANCE SPOR domain proteins are prominent components of the cell division apparatus in a wide variety of bacteria. The primary function of SPOR domains is targeting proteins to the division site, which they accomplish by binding to septal peptidoglycan. However, whether SPOR domains have any functions beyond septal targeting is unknown. Here, we show that SPOR domains vary in their PG binding affinities and that, at least in the case of the E. coli cell division protein DamX, having a high-affinity SPOR domain contributes to proper function.
Details
- Title: Subtitle
- Comparative Study of Bacterial SPOR Domains Identifies Functionally Important Differences in Glycan Binding Affinity
- Creators
- Atsushi Yahashiri - Roy J. and Lucille A. Carver College of MedicineGabriela M. Kaus - Roy J. and Lucille A. Carver College of MedicineDavid L. Popham - Virginia TechJon C. D. Houtman - Roy J. and Lucille A. Carver College of MedicineDavid S. Weiss
- Contributors
- Conrad W. Mullineaux (Editor)
- Resource Type
- Journal article
- Publication Details
- Journal of bacteriology, Vol.204(9), p.1
- Publisher
- American Society for Microbiology
- DOI
- 10.1128/jb.00252-22
- PMID
- 36005810
- PMCID
- PMC9487507
- ISSN
- 0021-9193
- eISSN
- 1098-5530
- Number of pages
- 18
- Grant note
- GM138630 / HHS | NIH | National Institute of General Medical Sciences (NIGMS) (https://doi.org/10.13039/100000057) GM125656 / HHS | NIH | National Institute of General Medical Sciences (NIGMS) (https://doi.org/10.13039/100000057) R21 AI157121 / HHS | NIH | National Institute of Allergy and Infectious Diseases (NIAID) (https://doi.org/10.13039/100000060) T32AI007511 / HHS | NIH | National Institute of Allergy and Infectious Diseases (NIAID) (https://doi.org/10.13039/100000060)
- Language
- English
- Date published
- 08/25/2022
- Academic Unit
- Microbiology and Immunology; Internal Medicine
- Record Identifier
- 9984297632602771
Metrics
14 Record Views