Molecular characterization of the Cassava brown streak virus coat protein

A partial sequence of 1114 nucleotides of a virus from cassava brown streak diseased (CBSD) material was obtained. Alignment of the predicted amino ac id sequence with those of other members of the Potyviridae showed closest i dentity with the coat protein of Sweet potato mild mottle virus (genus Ipom ovirus). The predicted amino acid sequence has one open reading frame with a 3' untranslated region of 144 nucleotides and a poly(A) tail. The express ed protein was shown to cross-react with an antiserum raised previously to a virus isolated from CBSD material. Evidence presented suggests that CBSD is caused by Cassava brown streak virus, a tentative member of the genus Ip omovirus, as this virus is consistently found associated with CBSD.