Using subfragments of the simian virus 40 (SV40) core origin, we demonstrate that two alternative modules exist for the assembly of T-antigen (T-ag) double hexamers. Pentanucleotides 1 and 3 and the early palindrome (EP) constitute one assembly unit, while pentanucleotides 2 and 4 and the AT-rich region constitute a second, relatively weak, assembly unit. Related studies indicate that on the un...

Suppose intruders are in a dark polygonal room and they can move arbitrarily fast, trying to avoid detection. A boundary 1-searcher can move along the polygon boundary, equipped with a flash light that she can direct in any direction. A polygon is searchable if there is a schedule for the searcher in order to detect the intruders no matter how they move. We identify three simple forbidden patte...

Rubella virus and simina virus 40 (SV40) were isolated from a newborn child suffering from neurological and anatomical anomalies. The SV40 isolate was very similar to SV40 strain 777 by electron microscopic, biological, and immunological criteria.

We investigated whether the VP1 protein of simian virus 40 binds to DNA. In vitro DNA-binding experiments clearly indicate that VP1 bound strongly to double-stranded and single-stranded DNA, with a higher affinity for the latter; additional experiments show that VP1 did not bind to a specific sequence of simian virus 40 DNA.

Treatment with interferon reduced the content of early virus-specific RNA, as well as the content of an early viral protein (T antigen), in monkey cells acutely infected with simian virus 40 (SV40). This unexpected finding suggests either that the action of interferon involves inhibition of the transcription of early SV40 messenger RNA, or that the SV40 genome contains a "proto-early" gene whos...