?
Functional domain of U62 and UL91 proteins Human herpesvirus 6A (HHV-6A) and HHV-6B are classified as roseoloviruses and are highly prevalent in the human population. Roseolovirus reactivation in an immunocompromised host can cause severe pathologies. Human cytomegalovirus (HCMV) is responsible for significant diseases in developing fetus as well as in an immunocompromised host. During their productive cycle, herpesviruses have a regulated temporal cascade of gene expression that can be divided into three general stages: immediate-early (IE), early (E), and late (L). Following viral DNA replication, late viral genes that mainly encode structural proteins start to be transcribed, ultimately leading to the assembly and release of infectious particles. This domain family is found in Human herpesvirus 6A and 6B (HHV-6A/B) as well as HCMV. Family members are shown to be involved in late gene expression such as UL91 in Human Cytomegalovirus. This functional domain is located on the N-terminal (1-71 amino acids) of full-length UL91. It has been found to suffice for transcriptional activation of true-late genes within the nucleus of infected cells. In other words, UL91 is fully functional as a 71-aa N-terminal polypeptide and This small 71-aa polypeptide contains all protein-protein interaction motifs crucial to mediate transcriptional activation.
|