A complex formed between cell components and an HSV structural polypeptide binds to a viral immediate early gene regulatory DNA sequence.

Transcription of HSV immediate early genes is stimulated by a virus structural protein, Vmw65, in a process that requires specific recognition of the sequence TAATGARAT (R = purine). Upon incubation of nuclear extracts of HSV-infected cells with a short DNA fragment containing TAATGARAT, a novel virus-induced protein-DNA complex (named IEC) was detected. Addition of virion extract, containing Vmw65, to nuclear extract from uninfected cells also resulted in the formation of IEC. Vmw65 is a component of IEC, which contains proteins bound specifically to TAATGARAT. Thus, Vmw65 and cellular factors combine to form a sequence-specific DNA-binding complex. This system provides a model for studies of the regulation of inducible cellular genes.