Specificity of TMV RNA encapsidation: in vitro coating of heterologous RNA by TMV protein.

Tobacco mosaic virus (TMV) RN.4 and TMV coat protein were reconstitut,ed in the presence of an excess of host RNA or turnip yellow mosaic virus (TYMV) RNA. TMV protein and its homologous RNA recognized each other specifically in the presence of an excess of host RNA, but when TMV RNA and TYMV RNA were mixed with protein, both RNAs were encapsidated. Indeed, at pH 6, TYMV RNA was recognized by TMV protein at, least as well as T&IV RNA itself. This suggests that, TYMV RNA like TMV RNA may possess a special sit.e recognized by TMV protein,