Kullik I, Jenni R, Berger-Bächi B
Institute for Medical Microbiology, University of Zürich, Gloriastr. 32, 8028, Zürich, Switzerland.
Gene. 1998 Sep 28;219(1-2):9-17. doi: 10.1016/s0378-1119(98)00404-1.
A gene cluster comprising the alanine racemase gene alr was identified 5' to the sigB operon in Staphylococcus aureus. It is flanked upstream by four ORFs of which one shows similarity to the dpj gene of Escherichia coli, and downstream by two ORFs of which the last shows similarity to the E. coli pemK gene. Preliminary data suggest that the seven ORFs orf1-orf2-orf3-dpj-alr-orf6-pemK may form an operon. Disruption of the proposed operon by insertional mutagenesis leads to a drastic loss in the d-alanine (d-Ala) substitution of lipoteichoic acid and to delayed autolysis, without affecting the d-Ala substitution of the wall teichoic acid.
在金黄色葡萄球菌中，一个包含丙氨酸消旋酶基因alr的基因簇被鉴定位于sigB操纵子的5'端。它的上游侧翼有四个开放阅读框（ORF），其中一个与大肠杆菌的dpj基因相似，下游侧翼有两个开放阅读框，其中最后一个与大肠杆菌的pemK基因相似。初步数据表明，这七个开放阅读框orf1-orf2-orf3-dpj-alr-orf6-pemK可能形成一个操纵子。通过插入诱变破坏该假定的操纵子会导致脂磷壁酸的d-丙氨酸（d-Ala）取代大幅减少以及自溶延迟，而不影响壁磷壁酸的d-Ala取代。
