Imamura N, Nakayama H
J Bacteriol. 1982 Aug;151(2):708-17. doi: 10.1128/jb.151.2.708-717.1982.
Mutants of Escherichia coli K-12 auxotrophic for thiamine phosphates were produced in stepwise fashion from the polyauxotrophic F- strain JC1552, via intermediate production of thiamine auxotrophs that had lost the enzymatic activity of either phosphomethylpyrimidine kinase or thiamine phosphate pyrophosphorylase. They include two types: one responds to thiamine monophosphate or thiamine pyrophosphate, and the other responds to thiamine pyrophosphate only; the former lacks thiamine kinase activity, and the latter lacks thiamine monophosphate kinase activity, in addition to the enzymatic defects caused by the first mutations. We found two genes, for which we propose the designations thiK and thiL, which govern the activities of thiamine kinase and thiamine monophosphate kinase, respectively. By conjugation and P1 transduction, the thiK locus was mapped at about 25 min, between pyrC and purB and close to fabD. The relative order of thiK with respect to nearby genes was tentatively established as pyrC-ptsG-fabD-thiK-purB. In the case of thiL, the locus was situated at about 9 min, between tsx and acrA and probably 0.2 min clockwise from the former.
从多营养缺陷型F-菌株JC1552逐步培育出了对硫胺磷酸盐营养缺陷的大肠杆菌K-12突变体，培育过程中会产生硫胺营养缺陷体，这些营养缺陷体失去了磷酸甲基嘧啶激酶或硫胺磷酸焦磷酸化酶的酶活性。它们包括两种类型：一种对硫胺单磷酸或硫胺焦磷酸有反应，另一种仅对硫胺焦磷酸有反应；前者缺乏硫胺激酶活性，后者除了具有首次突变导致的酶缺陷外，还缺乏硫胺单磷酸激酶活性。我们发现了两个基因，分别命名为thiK和thiL，它们分别控制硫胺激酶和硫胺单磷酸激酶的活性。通过接合和P1转导，thiK基因座定位在大约25分钟处，位于pyrC和purB之间且靠近fabD。thiK相对于附近基因的相对顺序初步确定为pyrC-ptsG-fabD-thiK-purB。对于thiL，该基因座位于大约9分钟处，在tsx和acrA之间，可能从前者顺时针方向0.2分钟处。
