Wagner E, Götz F, Brückner R
Mikrobielle Genetik, Universität Tübingen, Germany.
Mol Gen Genet. 1993 Oct;241(1-2):33-41. doi: 10.1007/BF00280198.
By insertional mutagenesis with the staphylococcal transposon Tn551, mutants of Staphylococcus xylosus were isolated that were unable to utilize sucrose. One of these was found to be deficient in sucrose uptake. The genomic region containing this sucrose uptake gene of Staphylococcus xylosus (scrA) was cloned in Staphylococcus carnosus. The scrA gene was further localized to a 4.4 kb DNA fragment by complementation of the sucrose transport-deficient S. xylosus mutant. The DNA sequence analysis of the scrA region revealed three open reading frames, one of which encodes a protein of 480 amino acids (51.335 kDa) with significant similarity to sucrose-specific Enzymes II of phosphoenolpyruvate-dependent carbohydrate phosphotransferase systems (PTS). A protein with an apparent molecular weight of 50 kDa was obtained in Escherichia coli by expression of scrA with the bacteriophage T7 RNA polymerase promoter system. Transcriptional start sites of the scrA gene were localized by primer extension analysis to positions 46 and 49 nucleotides upstream of the scrA start codon. No additional sucrose utilization genes are encoded close to scrA on the S. xylosus chromosome.
通过用葡萄球菌转座子Tn551进行插入诱变，分离出了不能利用蔗糖的木糖葡萄球菌突变体。其中一个被发现蔗糖摄取存在缺陷。含有木糖葡萄球菌（scrA）这种蔗糖摄取基因的基因组区域被克隆到肉葡萄球菌中。通过对蔗糖转运缺陷型木糖葡萄球菌突变体进行互补，scrA基因进一步定位到一个4.4 kb的DNA片段上。对scrA区域的DNA序列分析揭示了三个开放阅读框，其中一个编码一个480个氨基酸（51.335 kDa）的蛋白质，与磷酸烯醇丙酮酸依赖性碳水化合物磷酸转移酶系统（PTS）的蔗糖特异性酶II有显著相似性。通过用噬菌体T7 RNA聚合酶启动子系统表达scrA，在大肠杆菌中获得了一个表观分子量为50 kDa的蛋白质。通过引物延伸分析将scrA基因的转录起始位点定位到scrA起始密码子上游46和49个核苷酸的位置。在木糖葡萄球菌染色体上，靠近scrA没有编码其他蔗糖利用基因。
