NUCLEOTIDE-SEQUENCE OF A GENOMIC GENE ENCODING TRITIN, A RIBOSOME-INACTIVATING PROTEIN FROM TRITICUM-AESTIVUM

A genomic gene of tritin, a ribosome-inactivating protein (RIP) from T riticum aestivum, was cloned using a barley RIP gene as a probe. The 5 '-non-coding region has potential TATA boxes and three sequences homol ogous to the binding sequence of the transcriptional activator protein Opaque-2 which activates maize RIP gene expression. The cloned DNA en coded tritin consists of 275 amino acids with no secretion signal sequ ence. The coding region of tritin was expressed in Escherichia coli us ing lac promoter and yielded a protein similar to the native one, as d etermined by SDS-polyacrulamide gel electrophoresis and immunological analysis.