Comparison of MuLV glyco-gag amino acid sequences. Amino acid sequence alignments are shown for a representative FMR group virus (M-MuLV) and Xeno Clade B and C endogenous MuLVs at the top of the figure. For all of these cases, the glyco-gag reading frame is contiguous with the frame for Gag polyprotein. For Xeno Clade B and C, alignments are also shown for replication-competent viruses with high homology in the glyco-gag region (DG-75 MuLV and AKV-MuLV/Emv-2 respectively). *, amino acids shared among all of the glyco-gags. In the lower part of the figure (shaded box), predicted amino acids from endogenous MuLVs that cannot encode full-length glyco-gag are shown. The predicted open reading frames close before the beginning of the coding sequences for Gag polyprotein. *, predicted amino acids shared between these MuLVs and the glyco-gag positive MuLVs and MuLVs. The glyco-gag amino acid sequences in MuLVs were aligned by DNASTAR Lasergene 8 MegAlign (Clustal W method).