Hirato T, Shinagawa M, Ishiguro N, Sato G
J Bacteriol. 1984 Oct;160(1):421-6. doi: 10.1128/jb.160.1.421-426.1984.
A genetic determinant conferring on Escherichia coli the ability to utilize citrate as a sole source of carbon and energy was subcloned into pBR322 from a naturally occurring, citrate utilization (Cit+) plasmid, pOH30221, and was localized to a 1.6-kilobase region by cloning and subsequent deletion analysis. Genetic expression of the Cit+ determinant in E. coli minicells revealed that the Cit+ determinant encoded a single, membrane-associated polypeptide with an apparent molecular weight of 35,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This polypeptide seemed not to be synthesized as a precursor with an amino-terminal signal sequence.
一种赋予大肠杆菌利用柠檬酸盐作为唯一碳源和能源能力的遗传决定因子，从天然存在的柠檬酸盐利用（Cit +）质粒pOH30221亚克隆到pBR322中，并通过克隆和随后的缺失分析定位到一个1.6千碱基的区域。在大肠杆菌微小细胞中Cit +决定因子的基因表达表明，该Cit +决定因子编码一种单一的、与膜相关的多肽，通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳测定，其表观分子量为35000。该多肽似乎不是以前体形式与氨基末端信号序列一起合成的。
