Staphylococcus aureus FtsZ and PBP4 bind to the conformationally dynamic N-terminal domain of GpsB

• Published in: eLife Vol. 13
• Main Authors: Sacco, Michael D, Hammond, Lauren R, Noor, Radwan E, Bhattacharya, Dipanwita, McKnight, Lily J, Madsen, Jesper J, Zhang, Xiujun, Butler, Shane G, Kemp, M Trent, Jaskolka-Brown, Aiden C, Khan, Sebastian J, Gelis, Ioannis, Eswara, Prahathees, Chen, Yu
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 19.04.2024; eLife Sciences Publications Ltd; eLife Sciences Publications, Ltd
• Subjects: Bacteria; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Cell division; cell wall; Crystal structure; Crystallography, X-Ray; Crystals; Cytoskeletal Proteins - chemistry; Cytoskeletal Proteins - genetics; Cytoskeletal Proteins - metabolism; EzrA; GpsB recognition motif; Gram-positive bacteria; Life Sciences & Biomedicine - Other Topics; Membrane proteins; Methicillin; Microbiology and Infectious Disease; Models, Molecular; Mutants; Penicillin; penicillin-binding protein; Penicillin-Binding Proteins - chemistry; Penicillin-Binding Proteins - genetics; Penicillin-Binding Proteins - metabolism; Peptides; Peptidoglycans; Phenotypes; Protein Binding; Protein biosynthesis; Protein Conformation; Protein structure; Proteins; S. aureus; Staphylococcus aureus; Staphylococcus aureus - genetics; Staphylococcus aureus - metabolism; Staphylococcus aureus infections; Streptococcus infections; Structure; Structure-function relationships; Thermal stability; Australia; B. subtilis; S. aureus; DivIVA; EzrA; infectious disease; GpsB recognition motif; cell division; microbiology; penicillin-binding protein; cell wall; staphylococcus aureus
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.85579

In the Firmicutes phylum, GpsB is a membrane associated protein that coordinates peptidoglycan synthesis with cell growth and division. Although GpsB has been studied in several bacteria, the structure, function, and interactome of GpsB is largely uncharacterized. To address this knowledge gap, we solved the crystal structure of the N-terminal domain of GpsB, which adopts an atypical, asymmetric dimer, and demonstrates major conformational flexibility that can be mapped to a hinge region formed by a three-residue insertion exclusive to . When this three-residue insertion is excised, its thermal stability increases, and the mutant no longer produces a previously reported lethal phenotype when overexpressed in . In , we show that these hinge mutants are less functional and speculate that the conformational flexibility imparted by the hinge region may serve as a dynamic switch to fine-tune the function of the GpsB complex and/or to promote interaction with its various partners. Furthermore, we provide the first biochemical, biophysical, and crystallographic evidence that the N-terminal domain of GpsB binds not only PBP4, but also FtsZ, through a conserved recognition motif located on their C-termini, thus coupling peptidoglycan synthesis to cell division. Taken together, the unique structure of GpsB and its direct interaction with FtsZ/PBP4 provide deeper insight into the central role of GpsB in cell division.