RRC ID 35579
Author Williams KB, Yahashiri A, Arends SJ, Popham DL, Fowler CA, Weiss DS.
Title Nuclear magnetic resonance solution structure of the peptidoglycan-binding SPOR domain from Escherichia coli DamX: insights into septal localization.
Journal Biochemistry
Abstract 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 β-sheet buttressed on one side by two α-helices. A third helix, designated α3, associates with the other face of the β-sheet, but this helix is relatively mobile. Site-directed mutagenesis revealed the face of the β-sheet that interacts with α3 is important for septal localization and binding to PG sacculi. The position and mobility of α3 suggest it might regulate PG binding, but although α3 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.
Volume 52(4)
Pages 627-39
Published 2013-1-29
DOI 10.1021/bi301609e
PMID 23290046
PMC PMC3732209
MeSH Amino Acid Sequence Amino Acid Substitution Cell Division Conserved Sequence Deoxycholic Acid / pharmacology Escherichia coli / drug effects Escherichia coli / metabolism* Escherichia coli / physiology Escherichia coli Proteins / chemistry* Escherichia coli Proteins / genetics Escherichia coli Proteins / metabolism Models, Molecular Molecular Sequence Data Mutagenesis, Site-Directed Nuclear Magnetic Resonance, Biomolecular Peptidoglycan / chemistry* Protein Binding Protein Folding Protein Structure, Secondary Protein Structure, Tertiary Protein Transport Surface Properties
IF 2.865
Times Cited 10
Prokaryotes E. coli