Enomoto M, Oosawa K, Momota H
J Bacteriol. 1983 Nov;156(2):663-8. doi: 10.1128/jb.156.2.663-668.1983.
Although the vh2 mutation almost entirely prevents phase variation in Salmonella spp., an Escherichia coli strain that carried the Salmonella H1 and H2 region, including the vh2 mutation, showed phase variation. From this strain, EJ1076, a number of mutants defective in phase variation were isolated, and the symbol pin was assigned to their mutant gene. The pin locus was mapped between purB and trp near purB by interrupted matings using Tn10 sites inserted near pin. The locus was cotransduced with purB by P1 vir at a frequency of around 0.33. All the mutations tested were clustered at this locus. Three E. coli K-12 strains probably derived via different lines from the wild type have been tested for the presence of pin+ by introducing the two Salmonella H regions; two were pin+, and one was a pin mutant.
尽管vh2突变几乎完全阻止了沙门氏菌属的相变，但携带沙门氏菌H1和H2区域（包括vh2突变）的大肠杆菌菌株却表现出相变。从该菌株EJ1076中分离出了许多相变缺陷型突变体，并将其突变基因命名为pin。通过使用插入在pin附近的Tn10位点进行中断杂交，将pin位点定位在purB和trp之间靠近purB的位置。该位点通过P1噬菌体以约0.33的频率与purB共转导。所有测试的突变都聚集在该位点。通过引入两个沙门氏菌H区域，对可能通过不同品系从野生型衍生而来的三株大肠杆菌K-12菌株进行了pin+存在情况的测试；其中两株为pin+，一株为pin突变体。
