Tritz G J, Matney T S, Gholson R K
J Bacteriol. 1970 May;102(2):377-81. doi: 10.1128/jb.102.2.377-381.1970.
It is proposed that all mutants blocked in the de novo pathway of nicotinamide adenine dinucleotide biosynthesis be designated nad rather than nic. It is further suggested that mutants blocked in the pyridine nucleotide cycle be designated pnc. The nadB locus and a previously unidentified pur locus are cotransducible. These two loci have been mapped near minute 49 on the standard genetic map of Escherichia coli. The order of genes in that region is purC-guaB-purG-glyA-pur-nadB-tyrA-pheA.
建议将所有在烟酰胺腺嘌呤二核苷酸生物合成从头途径中受阻的突变体命名为nad,而不是nic。进一步建议将在吡啶核苷酸循环中受阻的突变体命名为pnc。nadB位点和一个先前未鉴定的pur位点是共转导的。这两个位点已定位在大肠杆菌标准遗传图谱上靠近49分钟处。该区域的基因顺序是purC-guaB-purG-glyA-pur-nadB-tyrA-pheA。