Forespore Targeting of SpoVD in Bacillus subtilis Is Mediated by the N-Terminal Part of the Protein

• Published in: Journal of bacteriology Vol. 200; no. 13
• Main Authors: Sidarta, Margareth, Li, Dongdong, Hederstedt, Lars, Bukowska-Faniband, Ewa
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01.07.2018
• Subjects: Amides; Amino Acid Motifs; Antibiotics; Bacillus subtilis; Bacillus subtilis - chemistry; Bacillus subtilis - genetics; Bacillus subtilis - growth & development; Bacillus subtilis - metabolism; Bacteria; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Binding; Binding sites; Biologi; Biological Sciences; Chimeras; Clinical microbiology; Cytoplasm; endospores; Food industry; Food processing industry; Membrane Transport Proteins - chemistry; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; Membranes; Microbiology; Mikrobiologi; Molecular chains; Molecular modelling; Natural Sciences; Naturvetenskap; Penicillin; penicillin-binding proteins; Penicillin-Binding Proteins - genetics; Penicillin-Binding Proteins - metabolism; Peptidoglycans; Probiotics; protein structure-function; protein targeting; Protein Transport; Proteins; Spores; Spores, Bacterial - chemistry; Spores, Bacterial - genetics; Spores, Bacterial - growth & development; Spores, Bacterial - metabolism; Sporulation; Synthesis; protein targeting; penicillin-binding proteins; protein structure-function; endospores; Bacillus subtilis; sporulation
• ISSN: 0021-9193; 1098-5530
• DOI: 10.1128/JB.00163-18

SpoVD and PBP4b are structurally very similar high-molecular-weight, class B penicillin-binding proteins produced early during sporulation in SpoVD is known to be essential for endospore cortex synthesis and thereby the production of heat-resistant spores. The role of PBP4b is still enigmatic. Both proteins are synthesized in the cytoplasm of the mother cell. PBP4b remains in the cytoplasmic membrane of the mother cell, whereas SpoVD accumulates in the forespore outer membrane. By the use of SpoVD/PBP4b chimeras with swapped protein domains, we show that the N-terminal part of SpoVD, containing the single transmembrane region, determines the forespore targeting of the protein. Beta-lactam-type antibiotics target penicillin-binding proteins (PBPs), which function in cell wall peptidoglycan synthesis. Bacteria of a subset of genera, including and species, can form endospores. The extreme resistance of endospores against harsh physicochemical conditions is of concern in clinical microbiology and the food industry. Endospore cortex layer biogenesis constitutes an experimental model system for research on peptidoglycan synthesis. The differentiation of a vegetative bacterial cell into an endospore involves the formation of a forespore within the cytoplasm of the sporulating cell. A number of proteins, including some PBPs, accumulate in the forespore. An understanding of the molecular mechanisms behind such subcellular targeting of proteins in bacterial cells can, for example, lead to a means of blocking the process of sporulation.