Nucleotide sequence of the Marek's disease virus (MDV) RB-1B A antigen gene and the identification of the MDV A antigen as the herpes simplex virus-1 glycoprotein C homologue.

The A antigen gene from a very virulent strain of Marek's disease virus, RB-1B, has been cloned and the nucleotide sequence determined. The predicted amino acid sequence showed 99% identity to that determined for the MDV GA A antigen (Coussens and Velicer, J. Virol. 62, 2373-2379, 1988) over all but the carboxy-terminal region where the sequence diverged extensively. The divergence results from three nucleotide frameshifts in the reported sequence of the MDV GA gene which are not present in a cloned copy of the MDV GA A antigen gene sequenced by us. The MDV A antigen shows significant homology to a number of herpes virus gC homologues, the homology being most extensive in the carboxy-halves of the proteins.