2LFV: Solution Structure of the SPOR domain from E. coli DamX

SPOR domains are present in thousands of bacterial proteins and probably bind septal peptidoglycan (PG), but the details of the SPOR-PG interaction have yet to be elucidated. Here we characterize the structure and function of the SPOR domain for an Escherichia coli division protein named DamX. Nuclear magnetic resonance revealed the domain comprises a four-stranded antiparallel beta-sheet buttressed on one side by two alpha-helices. A third helix, designated alpha3, associates with the other face of the beta-sheet, but this helix is relatively mobile. Site-directed mutagenesis revealed the face of the beta-sheet that interacts with alpha3 is important for septal localization and binding to PG sacculi. The position and mobility of alpha3 suggest it might regulate PG binding, but although alpha3 deletion mutants still localized to the septal ring, they were too unstable to use in a PG binding assay. Finally, to assess the importance of the SPOR domain in DamX function, we constructed and characterized E. coli mutants that produced DamX proteins with SPOR domain point mutations or SPOR domain deletions. These studies revealed the SPOR domain is important for multiple activities associated with DamX: targeting the protein to the division site, conferring full resistance to the bile salt deoxycholate, improving the efficiency of cell division when DamX is produced at normal levels, and inhibiting cell division when DamX is overproduced.
PDB ID: 2LFVDownload
MMDB ID: 101277
PDB Deposition Date: 2011/7/15
Updated in MMDB: 2012/07
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Biological Unit for 2LFV: monomeric; determined by author
Molecular Components in 2LFV
Label Count Molecule
Protein (1 molecule)
Protein Damx(Gene symbol: damX)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB