US22-like (IPR003360)

Short name: US22-like

Overlapping homologous superfamilies


Family relationships



Herpesviruses are large and complex DNA viruses, widely found in nature. Human cytomegalovirus (HCMV), an important human pathogen, defines the betaherpesvirus family. Mouse cytomegalovirus (MCMV) and rat cytomegalovirus serve as biological model systems for HCMV. HCMV, MCMV, and rat CMV display the largest genomes among the herpesviruses and are essentially co-linear over the central 180 kb of the 230-kb genomes. Betaherpesviruses, which include the CMVs as well as human herpesviruses 6 and 7, differ from alpha- and gammaherpesviruses by the presence of additional gene families such as the US22 gene family, which are mainly clustered at the ends of the genome. The US22 family was first described in HCMV. This gene family comprises 12 members in both HCMV and MCMV and 11 in rat CMV [PMID: 12719548].

US22 proteins have been found across many animal DNA viruses and some vertebrates [PMID: 21306995]. The name sake of this family US22 (P09722) is an early nuclear protein that is secreted from cells [PMID: 1321206]. The US22 family may have a role in virus replication and pathogenesis [PMID: 10405367]. Domain analysis showed that US22 proteins usually contain two copies of conserved modules which is homologous to several other families like SMI1 and SYD (commonly called SUKH superfamily). Bacterial operon analysis revealed that all bacterial SUKH members function as immunity proteins against various toxins. Thus US22 family is predicted to counter diverse anti-viral responses by interacting with specific host proteins [PMID: 21306995].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.