coat protein of Indian peanut clump virus: relationships with other furoviruses and with barley stripe mosaic virus

The 5'-most open reading frame of the c.4kb RNA-2 of Indian peanut clump furovirus (IPCV) encodes a protein of 208 amino acids. This protein is thought to be the coat protein of IPCV because its amino acid composition and M(r) closely resemble those reported for IPCV coat protein and because its amino acid sequence is 61% identical to that of the coat protein of peanut clump virus (PCV) from West Africa. The extent of the sequence identity between IPCV and PCV coat proteins confirms previous conclusions that the viruses are distinct rather than strains of one virus. The sequences of the coat proteins of IPCV and PCV were between 18% and 26% identical to those of other furoviruses and those of unrelated tobamoviruses and tobraviruses. In contrast, the coat protein sequences were 37% (IPCV) and 36% (PCV) identical to that of the coat protein of barley stripe mosaic hordeivirus (BSMV). This similarity between the coat proteins of viruses from different groups (= genera) is unusual but is consistent with previous reports of sequence relatedness in various genes between certain furoviruses and BSMV.