Araya-Kojima T, Ishibashi N, Shimamura S, Tanaka K, Takahashi H
Nutritional Science Laboratory, Morinaga Milk Industry Co., Ltd., Kanagawa, Japan.
Biosci Biotechnol Biochem. 1995 Jan;59(1):73-7. doi: 10.1271/bbb.59.73.
The complete nucleotide sequence of an open reading frame (ORF) preceding the Lactococcus lactis rpoD gene is reported. It was suggested that this ORF encodes Lactococcus lactis DNA primase and that the L. lactis rpoD operon consists of only two genes. Northern hybridization analysis showed that i) there are four mRNAs transcribing the rpoD gene (from upstream, M1-M4), ii) only the 3.7-kb transcript M1 includes the entire rpoD operon, iii) the shortest transcript M4 exists at both logarithmic and stationary phases of growth while the other three transcripts appear only at logarithmic phase, and iv) no apparent induction at the transcriptional level but transient repression of M1 was found when the growth temperature was shifted from 30 degrees C to 42 degrees C. 5'-ends of all four mRNAs were identified by primer extension analyses.
本文报道了乳酸乳球菌rpoD基因之前一个开放阅读框（ORF）的完整核苷酸序列。研究表明，该ORF编码乳酸乳球菌DNA引发酶，且乳酸乳球菌rpoD操纵子仅由两个基因组成。Northern杂交分析显示：i）有4种mRNA转录rpoD基因（从上游起，M1 - M4）；ii）仅3.7 kb的转录本M1包含完整的rpoD操纵子；iii）最短的转录本M4在对数生长期和稳定期均存在，而其他三种转录本仅在对数期出现；iv）当生长温度从30℃转变为42℃时，未发现转录水平有明显诱导，但M1出现短暂抑制。通过引物延伸分析确定了所有4种mRNA的5'端。
