Isolation of tobacco catalase isozyme 1 (salicylic acid binding protein) interacting with 2a polymerase of Cucumber mosaic virus

다국어 초록 (Multilingual Abstract)

2a protein encoded by RNA2 in CMV is a RNA-dependent RNA polymerase. It plays an important role in replication of virus RNA and determination of host specificity. In addition, the interaction between 2a polymerase and host factor(s) may play an important role in signal transduction pathway for plant defense system. To isolate host factor(s) interacting with 2a polymerase, it was screened tobacco cDNA pool using yeast two-hybrid system. As a result, a number of genes encoding protein have been found to interact with 2a polymerse. 44 clones were selected positively. One DNA fragment encode C-terminal portion of Catalase isozyme 1 (salicylic acid binding protein). It was isolated a complete ORF cDNA clone of Catalase isozyme 1 from Nicotiana tabacum cv Xanthi nc by RT-PCR method and was confirmed by yeast two-hybrid system and by GST pull-down assay. In addition, the essential region of the 2a protein and CAT 1 to interact with each other was characterized. In this result, the essential region to interact with the CAT 1 was the central GDD motif region and CAT N interacted with GDD motif region, like CAT C.