Complete sequence analysis of the two plasmids reveal that the small plasmid plp2000 with 2061 nucleotide encodes a putative 37 kda replicase . and in the downstream region of the replicase gene , it existed multi - tandem repeat of 17 bps Southernblot显示plp2000和plp9000两种质粒属于滚环复制类型质粒,和滚环复制相关的钻序列可能形成的二级结构分别为sso和ssou类型。