Bacteriophage P22 linear DNA molecules are a set of circularly permuted sequences with ends located in a limited region of the physical map. This mature form of the viral chromosome is cut in headful lengths from a concatemeric precursor during DNA encapsulation. Packaging of P22 DNA begins at a specific site, which we have termed pat, and then proceeds sequentially to cut lengths of DNA slight...

P22 tailspike is a homotrimeric, thermostable adhesin that recognizes the O-antigen lipopolysaccharide of Salmonella typhimurium. The 70 kDa subunits include long beta-helix domains. After residue 540, the polypeptide chains change their path and wrap around one another, with extensive interchain contacts. Formation of this interdigitated domain intimately couples the chain folding and assembly...

To determine the genotypes of Toxoplasma gondii strains associated with human toxoplasmosis, we developed a sensitive approach for typing parasites grown from clinical samples by short-term in vitro culture. A newly described nested PCR assay was capable of amplifying genomic DNA from as few as five parasites in the presence of host tissues. Typing was based on DNA polymorphisms at the SAG2 loc...

Outbred mice were vaccinated with various artificial Salmonella vaccines and subsequently challenged intraperitoneally with graded doses of virulent Salmonella typhimurium. The Salmonella vaccines used were: (i) octasaccharide, obtained by hydrolysis of the O-antigenic polysaccharide chain of S. typhimurium strain SH 4809 with phage P22-associated endo-rhamnosidase and covalently linked to eith...

Chronic granulomatous disease (CGD) is a congenital disorder in which phagocytes cannot generate superoxide (O2-) and other microbial oxidants due to mutations in any one of four components of the O2(-)-generating complex, NADPH oxidase. We report here a female CGD patient in whom a missense mutation in one of these components, the p22-phox subunit of the neutrophil membrane cytochrome b [where...