Expression of Rhizobium leguminosarum CFN42 genes for lipopolysaccharide in strains derived from different R. leguminosarum soil isolates.
Expression of Rhizobium leguminosarum CFN42 genes for lipopolysaccharide in strains derived from different R. leguminosarum soil isolates.
复制标题
豆科根瘤菌 CFN42 脂多糖基因在源自不同豆科根瘤菌土壤分离株的菌株中的表达。
DOI：
10.1128/jb.172.2.548-555.1990
复制
发表时间：
1990
影响因子：
3.2
通讯作者：
Noel,KD
中科院分区：
文献类型：
--
作者：
Brink,BA;Miller,J;Carlson,RW;Noel,KD
从大豆根瘤菌ANU843中分离到两株脂多糖缺陷突变株。两个突变体的内毒素都缺乏O抗原和部分内毒素核心寡糖残基。之前从另一个豆类根瘤菌野生型菌株CFN42中克隆的基因区域被用来补充这些突变。对一个突变体进行补充，得到了在抗原性、凝胶迁移率和糖组成方面与菌株ANU843的脂多糖明显相同的脂多糖。另一个突变体由第二个CFN42 LPS基因区补充。在这种情况下，产生的内毒素含有供体菌株CFN42特有的O-抗原糖，并与抗CFN42细胞的抗血清发生弱反应，但与ANU843细胞的抗血清不发生明显反应。因此，CFN42 LPs基因区域中的一个区域指定了在两个豆类根霉野生型分离物之间保守的功能，而另一个区域至少部分地指定了菌株特有的内毒素结构。将这两个基因区域转移到来自豆类根霉ANU843和128C53的野生型菌株中，结果与这一结论一致。菌株ANU843产生的突变体诱导的三叶草根瘤发育不完全，表现出低细菌数量和极低的固氮酶活性。当两个突变体携带CFN42 LPS DNA时，无论O抗原是否为ANU843菌株最初制造的抗原，它们都会诱发正常发育的固氮三叶草根瘤，这种DNA允许合成含有O抗原的内毒素。
Two mutant derivatives of Rhizobium leguminosarum ANU843 defective in lipopolysaccharide (LPS) were isolated. The LPS of both mutants lacked O antigen and some sugar residues of the LPS core oligosaccharides. Genetic regions previously cloned from another Rhizobium leguminosarum wild-type isolate, strain CFN42, were used to complement these mutants. One mutant was complemented to give LPS that was apparently identical to the LPS of strain ANU843 in antigenicity, electrophoretic mobility, and sugar composition. The other mutant was complemented by a second CFN42 lps genetic region. In this case the resulting LPS contained O-antigen sugars characteristic of donor strain CFN42 and reacted weakly with antiserum against CFN42 cells, but did not react detectably with antiserum against ANU843 cells. Therefore, one of the CFN42 lps genetic regions specifies a function that is conserved between the two R. leguminosarum wild-type isolates, whereas the other region, at least in part, specifies a strain-specific LPS structure. Transfer of these two genetic regions into wild-type strains derived from R. leguminosarum ANU843 and 128C53 gave results consistent with this conclusion. The mutants derived from strain ANU843 elicited incompletely developed clover nodules that exhibited low bacterial populations and very low nitrogenase activity. Both mutants elicited normally developed, nitrogen-fixing clover nodules when they carried CFN42 lps DNA that permitted synthesis of O-antigen-containing LPS, regardless of whether the O antigen was the one originally made by strain ANU843.