Mann B J, Akins R A, Lambowitz A M, Metzenberg R L
Department of Physiological Chemistry, University of Wisconsin, Madison 53706.
Mol Cell Biol. 1988 Mar;8(3):1376-9. doi: 10.1128/mcb.8.3.1376-1379.1988.
van+, a gene encoding a phosphorus-repressible phosphate permease, was isolated by its ability to complement nuc-1, a positive regulatory locus that normally regulates van+ expression. This was unexpected because the nuc-1 host already contained a resident van+ gene. Plasmids carrying van+ complemented a nuc-2 mutation as well. Probing of RNA from untransformed wild-type (nuc-1+) and constitutive (nuc-1c) strains by van+ probes indicated that levels of the van+ transcript were subject to control by nuc-1+. Probing of the same RNAs with a cosmid clone, containing approximately 15 kilobases of upstream and downstream DNA, revealed no other detectable phosphorus-regulated transcripts within this 40-kilobase region of the chromosome.
van⁺是一个编码磷抑制性磷酸盐通透酶的基因，它是通过其互补nuc-1（一个正常调节van⁺表达的正向调节位点）的能力而被分离出来的。这是出乎意料的，因为nuc-1宿主已经含有一个常驻的van⁺基因。携带van⁺的质粒也能互补nuc-2突变。用van⁺探针探测未转化的野生型（nuc-1⁺）和组成型（nuc-1c）菌株的RNA表明，van⁺转录本的水平受nuc-1⁺的控制。用一个包含约15千碱基上游和下游DNA的黏粒克隆探测相同的RNA，发现在染色体的这个40千碱基区域内没有其他可检测到的磷调节转录本。
