This family consists of several UL45 proteins. The herpes simplex virus UL45 gene encodes an 18 kDa virion envelope protein whose function remains unknown. It has been suggested that the 18 kDa UL45 gene product is required for efficient growth in the central nervous system at low doses and may play an important role under the conditions of a naturally acquired infection. This family also contains several Varicellovirus UL45 or gene 15 proteins. The Equine herpesvirus 1 UL45 protein represents a type II membrane glycoprotein which has been found to be non-essential for EHV-1 growth in vitro but deletion reduces the viruses' replication efficiency. Studies have shown that UL45 has a C-type lectin-like fold, suggesting that it might have a carbohydrate-binding function.
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