Distinct and Specific Role of NlpC/P60 Endopeptidases LytA and LytB in Cell Elongation and Division of .

Peptidoglycan (PG) is an essential lattice of the bacterial cell wall that needs to be continuously remodeled to allow growth. This task is ensured by the concerted action of PG synthases that insert new material in the pre-existing structure and PG hydrolases (PGHs) that cleave the PG meshwork at critical sites for its processing. Contrasting with that contains more than 35 PGHs, is a non-sporulating rod-shaped bacterium that is predicted to possess a minimal set of 12 PGHs.

PBP2b plays a key role in both peripheral growth and septum positioning in Lactococcus lactis.

Lactococcus lactis is an ovoid bacterium that forms filaments during planktonic and biofilm lifestyles by uncoupling cell division from cell elongation. In this work, we investigate the role of the leading peptidoglycan synthase PBP2b that is dedicated to cell elongation in ovococci. We show that the localization of a fluorescent derivative of PBP2b remains associated to the septal region and superimposed with structural changes of FtsZ during both vegetative growth and filamentation indicating that PBP2b remains intimately associated to the division machinery during the whole cell cycle.

Yeast Gdt1 is a Golgi-localized calcium transporter required for stress-induced calcium signaling and protein glycosylation.

Calcium signaling depends on a tightly regulated set of pumps, exchangers, and channels that are responsible for controlling calcium fluxes between the different subcellular compartments of the eukaryotic cell. We have recently reported that two members of the highly-conserved UPF0016 family, human TMEM165 and budding yeast Gdt1p, are functionally related and might form a new group of Golgi-localized cation/Ca(2+) exchangers. Defects in the human protein TMEM165 are known to cause a subtype of Congenital Disorders of Glycosylation.

Structure of the LdcB LD-carboxypeptidase reveals the molecular basis of peptidoglycan recognition.

Peptidoglycan surrounds the bacterial cytoplasmic membrane to protect the cell against osmolysis. The biosynthesis of peptidoglycan, made of glycan strands crosslinked by short peptides, is the target of antibiotics like β-lactams and glycopeptides. Nascent peptidoglycan contains pentapeptides that are trimmed by carboxypeptidases to tetra- and tripeptides.

Binding mechanism of the peptidoglycan hydrolase Acm2: low affinity, broad specificity.

Peptidoglycan hydrolases are bacterial secreted enzymes that cleave covalent bonds in the cell-wall peptidoglycan, thereby fulfilling major physiological functions during cell growth and division. Although the molecular structure and functional roles of these enzymes have been widely studied, the molecular details underlying their interaction with peptidoglycans remain largely unknown, mainly owing to the paucity of appropriate probing techniques. Here, we use atomic force microscopy to explore the binding mechanism of the major autolysin Acm2 from the probiotic bacterium Lactobacillus plantarum.