摘要
质粒pBN119的3.2kb BamHI片段的PvuⅡ-BglⅡ片段全顺序长为840bp,其中含油菜叶绿体16S rRNA基因5′端的140bp。通过寻找GTTC顺序,发现在395至468位核苷酸之间是tRNA^(Val)基因;在73至118位核苷酸之间是一个蛋白阅读框。和已发表的玉米叶绿体16S rRNA前导顺序进行比较,同样存在三个相应的大肠杆菌RNA聚合酶的结合位点。和大肠杆菌的启动子及相应基因作比较,表明叶绿体基因组具有很明显的原核性,但其tRNA^(Val)基因没有CCA3′顺序。在16S rRNA基因、tRNA^(Val)基因及蛋白阅读框的5′端附近均能找到一个比较稳定的茎环结构。我们推测这些茎环结构可能和位于反问重复顺序上的某些基因的转录调节有关。
The 840bp leading sequence of 16S rRNA gene (including 140bp 16S rRNA Rene) was sequenced Screening for structure elements common to tRNA reveals a gene coding for tRNAval An open reading frame,and three E.coli RNA polymerase binding sites were found.In front of the open reading frame,the tRNAvaj gene,and the 16S rRNA gene,a stable stemloop structrue can be formed.We suggested that these stem-loop structures may have some effect on the gene transcription which are licated on the inverted repeat sequence in chlorop-last.
