YidC/Oxa/Alb3 family proteins catalyze the insertion of integral membrane proteins in bacteria, mitochondria, and chloroplasts, respectively. Unlike gram-negative organisms, gram-positive bacteria express 2 paralogs of this family, YidC1/SpoIIIJ and YidC2/YgjG. In Streptococcus mutans, deletion of yidC2 results in a stress-sensitive phenotype similar to that of mutants lacking the signal recogn...

Pathogenic bacteria secrete various virulence factors, including toxins, lipases and proteases that allow them to infect, breakdown and colonize host tissue. Among various modes of action that the pathogenic bacteria use to damage the host, pore formation (by pore forming toxins (PFTs)) and lipid hydrolysis (by phospholipases) modes are common in damaging the eukaryotic cell membrane. PFTs in t...

The cell surface of most Gram-negative bacteria is covered with lipopolysaccharide (LPS). The network of charges and sugars provided by the dense packing of LPS molecules in the outer leaflet of the outer membrane interferes with the entry of hydrophobic compounds into the cell, including many antibiotics. In addition, LPS can be recognized by the immune system and plays a crucial role in many ...

Enucleated human polymorphonuclear leukocytes (PMN) were prepared by centrifuging isolated, intact PMN over a discontinuous Ficoll gradient that contained 20 microM cytochalasin B. The enucleated cells (PMN cytoplasts) contained about one-third of the plasma membrane and about one-half of the cytoplasm present in intact PMN. The PMN cytoplasts contained no nucleus and hardly any granules. The v...