Hani E K, Ng D, Chan V L
Department of Medical Genetics and Microbiology, University of Toronto, ON, Canada.
Can J Microbiol. 1999 Nov;45(11):959-69.
Arginine biosynthetic genes from Campylobacter jejuni TGH9011 were cloned by functional complementation of the respective Escherichia coli arginine biosynthetic mutants. Complementation of argA, argB, argC, argD, argE, argF, and argH auxotrophs was accomplished using a pBR322-based C. jejuni TGH9011 plasmid library. By cross-complementation analyses, the first four steps of arginine biosynthesis were shown to be closely linked on the genome. Two additional clones complementing the first (ArgA) and fifth (ArgE) steps in arginine biosynthesis were obtained. Neither recombinant showed linkage to the arg cluster, to each other, nor to other arginine biosynthetic functions by cross-complementation. Genes argF and argH were not linked to other arginine biosynthetic genes by cross-complementation analysis. Restriction enzyme patterns of recombinant plasmids fell into five groups. Group I contained the arg(ABCD) complementing locus. Group II and Group III were the two genetic loci corresponding to the argA and argE complementing genes. Group II contains the hipO gene encoding N-benzoylglycine-amino-acid amidohydrolase, also known as hippurate hydrolase. Group III contains the hipO homolog of C. jejuni. Group IV represents the argF gene. Group V is the argH gene. Functional complementation of mutations in the first four steps of the arginine biosynthetic pathway was obtained on recombinant plasmid pARGC2. The predicted order of gene complementation was argCargA(argBargD). The sequence of the insert in plasmid pARGC2 revealed direct homologs for argC, argB, and argD. However, sequence analysis of the gene complementing ArgA function in two separate E. coli argA mutants determined that the C. jejuni gene was not a canonical argA gene. The gene complementing the argA defect, which we call argO, showed limited homology to the streptothricin acetyltransferase gene (sat) of Escherichia coli. The flanking open reading frames in pARGC2 showed no homologies to arginine biosynthetic genes. The structure of the argCOBD gene arrangement is discussed with reference to the presence and location of other arginine biosynthetic genes on the genome of C. jejuni and other bacterial organisms.
通过对相应的大肠杆菌精氨酸生物合成突变体进行功能互补，克隆了空肠弯曲菌TGH9011的精氨酸生物合成基因。使用基于pBR322的空肠弯曲菌TGH9011质粒文库实现了对argA、argB、argC、argD、argE、argF和argH营养缺陷型的互补。通过交叉互补分析表明，精氨酸生物合成的前四个步骤在基因组上紧密相连。获得了另外两个克隆，它们分别互补精氨酸生物合成的第一步（ArgA）和第五步（ArgE）。通过交叉互补，这两个重组体均未显示与arg簇、彼此之间或其他精氨酸生物合成功能存在连锁关系。通过交叉互补分析，argF和argH基因未与其他精氨酸生物合成基因连锁。重组质粒的限制性酶切图谱分为五组。第一组包含arg(ABCD)互补位点。第二组和第三组是与argA和argE互补基因相对应的两个基因位点。第二组包含编码N-苯甲酰甘氨酸-氨基酸酰胺水解酶（也称为马尿酸盐水解酶）的hipO基因。第三组包含空肠弯曲菌的hipO同源物。第四组代表argF基因。第五组是argH基因。在重组质粒pARGC2上实现了精氨酸生物合成途径前四个步骤中突变的功能互补。基因互补的预测顺序为argCargA(argBargD)。质粒pARGC2中插入片段的序列揭示了argC、argB和argD的直接同源物。然而，对两个独立的大肠杆菌argA突变体中互补ArgA功能的基因进行序列分析后确定，空肠弯曲菌基因不是典型的argA基因。互补argA缺陷的基因（我们称为argO）与大肠杆菌的链丝菌素乙酰转移酶基因（sat）具有有限的同源性。pARGC2中的侧翼开放阅读框与精氨酸生物合成基因无同源性。结合空肠弯曲菌和其他细菌生物体基因组上其他精氨酸生物合成基因的存在和位置，讨论了argCOBD基因排列的结构。
