Identification of the SV40 agnogene product: a DNA binding protein.

Abstract

The proximal late region of the SV40 genome (map positions 0.72–0.76) contains an open nucleotide reading frame1,2 called the agnogene3 because its product had so far not been detected. We report here the detection of a novel protein of molecular weight (Mr) 7,900 (61 amino acids) in cells lytically infected by SV40; its identity has been confirmed by comparing the amino-terminal sequence with that predicted from the SV40 nucleotide sequence. This so-called agnoprotein accumulates late in the lytic cycle and has a relatively short half life of ∼2 h. The highly basic nature of the protein and its affinity for both single-stranded and double-stranded DNA suggests that it may have a regulatory role in nucleic acid–protein interactions.