Kedzierska S, Wawrzynów A, Taylor A
Laboratory of Bacterial Biochemistry, Department of Biochemistry, University of Gdánsk, Poland.
Gene. 1996 Feb 2;168(1):1-8. doi: 10.1016/0378-1119(95)00712-1.
The Rz1 gene of bacteriophage lambda is located within the Rz1 lysis gene. It codes for the 6.5-kDa prolipoprotein (Rz1) which undergoes N-terminal signal sequence cleavage and post-translational lipid modification of the N-terminal Cys of the mature protein. Globomycin, the antibiotic which inhibits bacterial signal peptidase II, specific for prolipoproteins containing diacylglyceryl cysteine [Hayashi and Wu, J. Bioenerg. Biomembr. 22 (1990) 451-471] inhibits the N-terminal sequence cleavage of the Rz1 precursor. The mature protein is rich in Pro, which constitutes 25% of its amino acids (aa). Using a computer-predicted, synthetic, 15-aa antigenic determinant of Rz1 polyclonal anti-Rz[46-60] antibodies, were obtained, and employed to localize Rz1 in bacterial fractions. In induced Escherichia coli lambda lysogens Rz1 was found almost exclusively in the outer membrane (OM). In a strain overproducing Rz1 from the pSB54 plasmid, it was distributed in all the fractions, OM, fraction A and inner membrane (IM). Expression of Rz1 from the pSB54 caused enlargement of fraction A, corresponding to the adhesion sites of OM and IM. Such an enlargement was previously observed in induced lambda lysogens, shortly before the onset of lysis.
噬菌体λ的Rz1基因位于Rz1裂解基因内。它编码6.5 kDa的前脂蛋白（Rz1），该前脂蛋白会经历N端信号序列的切割以及成熟蛋白N端半胱氨酸的翻译后脂质修饰。球蛋白是一种抗生素，可抑制细菌信号肽酶II，对含有二酰甘油半胱氨酸的前脂蛋白具有特异性[林和吴，《生物能量学与生物膜杂志》22 (1990) 451 - 471]，它能抑制Rz1前体的N端序列切割。成熟蛋白富含脯氨酸，脯氨酸占其氨基酸（aa）的25%。利用计算机预测的Rz1的15个氨基酸的合成抗原决定簇，获得了多克隆抗Rz[46 - 60]抗体，并用于在细菌组分中定位Rz1。在诱导的大肠杆菌λ溶源菌中，Rz1几乎只存在于外膜（OM）中。在一个从pSB54质粒过量产生Rz1的菌株中，它分布在所有组分中，即外膜、组分A和内膜（IM）。从pSB54中表达Rz1导致组分A增大，这与外膜和内膜的黏附位点相对应。这种增大之前在诱导的λ溶源菌中裂解开始前不久就观察到了。
