Further studies will be required to understand why UL18, alone among viral class I MHC homologs, associates with endogenous peptides and what effects peptide binding has on the HCMV lifecycle and the host anti-viral immune response.
—Structure of UL18, a peptide-binding viral MHC mimic, bound to a host inhibitory receptor.
Zhiru Yang and Pamela J. Bjorkman.
PNAS July 22, 2008 vol. 105 no. 29 10095-10100. doi:10.1073/pnas.0804551105
Structure of UL18 (see below; click for larger versions) is highly similar to vertebrate MHC class I molecules. For more, see A Field Guide to the MHC Family.
| Human cytomegalovirus UL18 | HLA-A2 | |
| Side view |  |
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| Top view (Peptide in green) |
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