Amino- and carboxyl-terminal sequences of proteins coded by gag gene of endogenous baboon and cat type c viruses

Abstract

Abstract The amino- and carboxyl-terminal amino acid sequences of proteins (p10, p12, p15, and p30) coded by the gag gene of endogenous baboon and eat type C viruses were determined. Among these proteins, p12 from both viruses appears to have a blocked amino terminus. Proline was found to be the common amino end of both p30s and of cat p15, while alanine is the amino terminus of baboon p15 and both p10s. The amino-terminal sequences of the p30s differ at only one of the first 27 residues, while the p15s and p10s are distinctive but show substantial homology. Leucine was found to be the carboxyl-terminal amino acid for p10, p12, and p30 from both viruses, while phenylalanine is the carboxyl-terminus of both p15s. Based on these amino acid sequences and the previously proposed H-p12-p15-p30-p10-C00H polypeptide sequence in the precursor polyprotein, a model (similar to that suggested for mouse type C viruses) for proteolytic cleavage sites involved in the post translational processing of the precursor coded for by the gag vene is Dronosed.