Spitzer E D, Weiss B
J Bacteriol. 1985 Dec;164(3):994-1003. doi: 10.1128/jb.164.3.994-1003.1985.
The cloned dfp gene complements dna-707 (now designated dfp-707), a temperature-sensitive conditionally lethal mutation that results in a slow cessation of DNA synthesis while protein synthesis is maintained. In vitro and in vivo experiments failed to demonstrate a specific defect in the initiation of DNA replication, and turn-off of DNA synthesis at high temperature was slower than that of a typical initiation (dnaA) mutant. The gene was localized, and its product was identified through the construction and analysis of deletion and insertion mutants of dfp-containing plasmids. dfp is located between the rpmB and dut genes at 81 min on the linkage map of Escherichia coli K-12. It is transcribed clockwise, independently of dut. The ability of a plasmid to complement a chromosomal dfp-707 mutation was correlated with its ability to produce a 45-kilodalton polypeptide. The purified protein contained 1 mol of flavin mononucleotide per mol of polypeptide.
克隆的dfp基因可弥补dna - 707（现命名为dfp - 707），这是一种温度敏感的条件致死突变，会导致DNA合成缓慢停止，而蛋白质合成仍能维持。体外和体内实验均未证明DNA复制起始存在特定缺陷，且高温下DNA合成的关闭比典型的起始（dnaA）突变体要慢。该基因被定位，并通过构建和分析含dfp质粒的缺失和插入突变体来鉴定其产物。dfp位于大肠杆菌K - 12连锁图谱上81分钟处的rpmB和dut基因之间。它按顺时针方向转录，与dut无关。质粒弥补染色体dfp - 707突变的能力与其产生45千道尔顿多肽的能力相关。纯化后的蛋白质每摩尔多肽含有1摩尔黄素单核苷酸。
