Following contact with a eucaryotic cell, Yersinia species pathogenic for humans (Y. pestis, Y. pseudotuberculosis, and Y. enterocolitica) export and translocate a distinct set of virulence proteins (YopE, YopH, YopJ, YopM, and YpkA) from the bacterium into the eucaryotic cell. During in vitro growth at 37 degrees C in the presence of calcium, Yop secretion is blocked; however, in the absence o...

Defining transcriptional regulatory signals represents an essential step toward our understanding of eucaryotic gene expression. Analysis of genes transcribed by polymerase II has revealed a complex and interrelated set of “promoter elements.” Enhancers or activators are among the set of eucaryotic promoter elements that appear to increase transcriptional efficiency in a manner relatively indep...

We recognize organisms first and foremost by their forms, but how they grow and shape themselves still largely passes understanding. The objective of this article is to survey what has been learned of morphogenesis of walled eucaryotic microorganisms as a set of problems in cellular heredity, biochemistry, physiology, and organization. Despite the diversity of microbial forms and habits, some c...

Studies were conducted to determine whether encephalomyocarditis virus infection causes proteolytic cleavage of any of the polypeptides which comprise eucaryotic initiation factor 4F. Since no such alterations in the components of the initiation factor were detected, these observations confirmed that the mechanisms whereby encephalomyocarditis virus and poliovirus shut off host translation are ...

Blue-green algal mats incubated anaerobically rapidly produce large amounts of volatile sulfur compounds, including hydrogen sulfide, methyl mercaptan, and dimethyl sulfide. The major organic sulfur compound is methyl mercaptan, in contrast to previous results with marine eucaryotic algae. Light inhibited production of volatile sulfur compounds, apparently because the algae then produced O2, re...

Recent work has shown that the proliferating cell nuclear antigen (PCNA) is an essential component for the replication of the eucaryotic virus, SV40, in a human cell extract. This is due to its interaction with a hitherto overlooked DNA polymerase (pol <5), and this discovery has brought these two proteins under the scrutiny of those working in the cell cycle, replication and DNA polymerase fie...