A single amino acid exchange transfers VP16-induced positive control from the Oct-1 to the Oct-2 homeo domain.

摘要: The selective association of the herpesvirus trans-activator VP16 with human Oct-1 homeo domain is a model for differential positive transcriptional control by domains. discriminates between closely related domains and Oct-2 distinguishing among their seven amino-acid differences; these differences lie on surface that thought to be accessible when bound DNA. Only two are recognized VP16, one in each first alpha-helices tri-alpha-helical domain. major determinant vitro VP16-induced vivo single glutamic acid residue at position 22 alpha-helix domain, but acidic properties this not critical or vivo, because it can replaced glutamine little no deleterious effect. Mere replacement corresponding alanine key sufficient confer ability associate respond vivo. Thus, specificity conferred amino difference.